# data[].attributes.body
I chose this lesson out of the two because it hits numerous 21st century skills and more compared to the other. Even though there is more thought that goes into this lesson I like how it is interactive and fun for the children, plus they get hot chocolate! I feel like this lesson it teaches is important and is a great way to teach students these skills needed for science.

- Kaylee Garman

# data[].attributes.attachment_link.readable_text
I love my girls' natural curiosity when it comes to science. So, when my daughter asked me "Can we do a hot chocolate science experiment?" I knew it was time to get creative.

Working together, we came up with an amazing STEM activity.

When we make instant hot chocolate, we dissolve the contents of the packet into hot water. We decided to find out if temperature affected the speed that it dissolves.

Let's get started!

Disclosure: There are Amazon Affiliate and other affiliate links in this article which means, at no additional cost to you, we could receive compensation for our recommendations. You can read our full disclosure policy on our Disclosure Page for more details.

Supplies Needed for Your Hot Chocolate Science Project

First we needed to gather our supplies. Luckily most of the items were already in our kitchen.

Here's what you'll need:

Three heat-proof mugs
Three packets of instant hot chocolate
Measuring cup
Water
Spoons
Stopwatch or timer
Notebook for recording your results.

How to Do Your Hot Chocolate Science Experiment

We started our experiment by making a prediction. Which temperature of water would dissolve the hot chocolate the quickest?

The girls made their prediction (they chose hot) and then it was time to experiment.

We started by emptying our hot chocolate packets into our mugs, one packet per mug. Then we moved on to testing the different temperatures of water.

We tested each temperature, one at a time. We were very vague with our temperatures, using ice cold water, room temperature water, and hot water. You can always add a kitchen thermometer to measure the temperature of the water to add an extra measurement element to your experiment.

My girls took turns measuring the water, stirring, and operating the stopwatch. We used the digital stopwatch on my phone to time how long the hot chocolate took to dissolve.

For each cup, we measured 6 oz. of water. We used cold water from our refrigerator over ice, lukewarm water from the tap, and I did my grown-up duty and heated water in the microwave for the last mug.

Once the water was added to a mug, one girl started the stopwatch and the other started stirring. We stopped the stopwatch as soon as we saw the hot chocolate had dissolved.

Does Hot Chocolate Dissolve Faster in Hot Water or Cold Water?

We started with the ice cold water. My oldest daughter was in charge of the stirring. She stirred and stirred and stirred some more. It wouldn't dissolve. Eventually, we made the decision to stop after three minutes. You can see the results above. Disgusting!

We moved on to the room temperature water, which clocked in at 1 minute 38 seconds. And, then the hot water, which only took 28 seconds.

The results: hot water takes the least amount of time. We predicted that because the instructions said to use hot water when we made hot chocolate. (And, it's called hot chocolate after all...) But, now we know why we need to use hot water.

Why Does Hot Chocolate Powder Dissolve Faster in Hot Water?

Hot water has more energy than cold water. With more energy, the molecules in the water move faster breaking down the hot chocolate mix quicker.

Once we finished writing our results, we unceremoniously dumped the cold water hot chocolate sludge down the kitchen sink. Ick.

What happened to the other two mugs? They were topped with a dollop of whipped cream and enjoyed!

Our hot chocolate science experiment and turned out great!

More STEAM Activities to Try
Hockey Science Christmas Science: Grow the Grinch's Heart Edible STEM Projects for Kids Marshmallow Engineering STEAM Building Challenge 28 Awesome STEM Challenges for the Elementary Classroom at Teach Junkie
STEM Activities for Kids in the Kitchen at iGame Mom

Do more science at home:

We love Green Kid Crafts boxes because they provide easy, ready-to-do STEM activities we can try at home. You'll receive easy-to-follow instructions plus the supplies that you need for up to 6 activities. You can get a monthly subscription or buy a single themed box. If you enjoyed our hot chocolate science experiment, you may enjoy the Kitchen Science or the monthly Discovery Box subscription.

Click here for the Kitchen Science box.

Click here for the monthly Discovery Box subscription.

Are you looking for more activities?

Join our fun Facebook community, Creative Family Fun for Busy Families, for daily activities that are great for kids and families. We'll chat, share, and have fun. It's a safe and private place to share idea for family and kids activities. I'd love for you to join me! Just click the link below, request to join, and answer the questions (they're easy, I promise). Come join the fun! Join the Creative Family Fun for Busy Families community here.

The following two tabs change content below.

# data[].attributes.attachment_link.description
This hot chocolate science experiment is a fun way to learn about how temperature affects the rate at which hot chocolate dissolves.

# data[].attributes.body
This feels like a great introductory lesson for Stem because it involves simple materials with advanced processes. Students can learn scientific vocabulary while following a simple, step-by-step process. -Deborah

# data[].attributes.attachment_link.readable_text
What's cheaper than a Peep? Jelly beans! They're everywhere and after Easter, stores mark them half off. I have 3 Easter science activities to share with you today that are awesome for your elementary students. Keep it simple or take them to the next level!

Solubility

The first activity addresses solutions, solutes, solvents, and concentration. There are several ways you can do this, but here is one of them.
Use different amounts of warm water (100ml and 25ml) to dissolve 2 jelly bean candy shells. (A little white part will remain that you can toss.) You can use *strong* baggies or cups for the water. Identify how the transparency of the color depends on the concentration.

Physical Properties

Identify the physical properties of a jelly bean. Mix them together in a group. Do the physical properties of the jelly bean change? Place the jelly bean in water. How do the physical properties of the jelly bean change?

Jelly Bean Towers

Provide each student with 10 toothpicks and 10 jelly beans. The challenge to create the tallest stable tower possible. There must be a jelly bean at the top of the tower. Identify weak levels and strong levels. Provide students an opportunity to draw their designs and refine them.

Happy Easter!

# data[].attributes.attachment_link.title
Easter Science Activities with Jelly Beans

# data[].attributes.attachment_link.description
What's cheaper than a Peep? Jelly beans! They're everywhere and after Easter, stores mark them half off. I have 3 Easter science activities to share with you today that are awesome for your elementary students. Keep it simple or take them to the next level! The first activity addresses solutions, solutes, solvents, and concentration.

# data[].attributes.body
I chose this lesson because of how interactive it is. This lesson also hits multiple of the 21st Century Skills which is important. Most children enjoy hot chocolate as well so I think this would be something that would keep them interested.

# data[].attributes.attachment_link.readable_text
I love my girls' natural curiosity when it comes to science. So, when my daughter asked me "Can we do a hot chocolate science experiment?" I knew it was time to get creative.

Working together, we came up with an amazing STEM activity.

When we make instant hot chocolate, we dissolve the contents of the packet into hot water. We decided to find out if temperature affected the speed that it dissolves.

Let's get started!

Disclosure: There are Amazon Affiliate and other affiliate links in this article which means, at no additional cost to you, we could receive compensation for our recommendations. You can read our full disclosure policy on our Disclosure Page for more details.

Supplies Needed for Your Hot Chocolate Science Project

First we needed to gather our supplies. Luckily most of the items were already in our kitchen.

Here's what you'll need:

Three heat-proof mugs
Three packets of instant hot chocolate
Measuring cup
Water
Spoons
Stopwatch or timer
Notebook for recording your results.

How to Do Your Hot Chocolate Science Experiment

We started our experiment by making a prediction. Which temperature of water would dissolve the hot chocolate the quickest?

The girls made their prediction (they chose hot) and then it was time to experiment.

We started by emptying our hot chocolate packets into our mugs, one packet per mug. Then we moved on to testing the different temperatures of water.

We tested each temperature, one at a time. We were very vague with our temperatures, using ice cold water, room temperature water, and hot water. You can always add a kitchen thermometer to measure the temperature of the water to add an extra measurement element to your experiment.

My girls took turns measuring the water, stirring, and operating the stopwatch. We used the digital stopwatch on my phone to time how long the hot chocolate took to dissolve.

For each cup, we measured 6 oz. of water. We used cold water from our refrigerator over ice, lukewarm water from the tap, and I did my grown-up duty and heated water in the microwave for the last mug.

Once the water was added to a mug, one girl started the stopwatch and the other started stirring. We stopped the stopwatch as soon as we saw the hot chocolate had dissolved.

Does Hot Chocolate Dissolve Faster in Hot Water or Cold Water?

We started with the ice cold water. My oldest daughter was in charge of the stirring. She stirred and stirred and stirred some more. It wouldn't dissolve. Eventually, we made the decision to stop after three minutes. You can see the results above. Disgusting!

We moved on to the room temperature water, which clocked in at 1 minute 38 seconds. And, then the hot water, which only took 28 seconds.

The results: hot water takes the least amount of time. We predicted that because the instructions said to use hot water when we made hot chocolate. (And, it's called hot chocolate after all...) But, now we know why we need to use hot water.

Why Does Hot Chocolate Powder Dissolve Faster in Hot Water?

Hot water has more energy than cold water. With more energy, the molecules in the water move faster breaking down the hot chocolate mix quicker.

Once we finished writing our results, we unceremoniously dumped the cold water hot chocolate sludge down the kitchen sink. Ick.

What happened to the other two mugs? They were topped with a dollop of whipped cream and enjoyed!

Our hot chocolate science experiment and turned out great!

More STEAM Activities to Try
Hockey Science Christmas Science: Grow the Grinch's Heart Edible STEM Projects for Kids Marshmallow Engineering STEAM Building Challenge 28 Awesome STEM Challenges for the Elementary Classroom at Teach Junkie
STEM Activities for Kids in the Kitchen at iGame Mom

Do more science at home:

We love Green Kid Crafts boxes because they provide easy, ready-to-do STEM activities we can try at home. You'll receive easy-to-follow instructions plus the supplies that you need for up to 6 activities. You can get a monthly subscription or buy a single themed box. If you enjoyed our hot chocolate science experiment, you may enjoy the Kitchen Science or the monthly Discovery Box subscription.

Click here for the Kitchen Science box.

Click here for the monthly Discovery Box subscription.

Are you looking for more activities?

Join our fun Facebook community, Creative Family Fun for Busy Families, for daily activities that are great for kids and families. We'll chat, share, and have fun. It's a safe and private place to share idea for family and kids activities. I'd love for you to join me! Just click the link below, request to join, and answer the questions (they're easy, I promise). Come join the fun! Join the Creative Family Fun for Busy Families community here.

The following two tabs change content below.

# data[].attributes.attachment_link.description
This hot chocolate science experiment is a fun way to learn about how temperature affects the rate at which hot chocolate dissolves.

# data[].attributes.body
I chose this one as opposed to the jelly bean one because of the amount of 21st century skills it includes. I also like it because it can be used to cover multiple science topics.
-Avery

# data[].attributes.attachment_link.readable_text
I love my girls' natural curiosity when it comes to science. So, when my daughter asked me "Can we do a hot chocolate science experiment?" I knew it was time to get creative.

Working together, we came up with an amazing STEM activity.

When we make instant hot chocolate, we dissolve the contents of the packet into hot water. We decided to find out if temperature affected the speed that it dissolves.

Let's get started!

Disclosure: There are Amazon Affiliate and other affiliate links in this article which means, at no additional cost to you, we could receive compensation for our recommendations. You can read our full disclosure policy on our Disclosure Page for more details.

Supplies Needed for Your Hot Chocolate Science Project

First we needed to gather our supplies. Luckily most of the items were already in our kitchen.

Here's what you'll need:

Three heat-proof mugs
Three packets of instant hot chocolate
Measuring cup
Water
Spoons
Stopwatch or timer
Notebook for recording your results.

How to Do Your Hot Chocolate Science Experiment

We started our experiment by making a prediction. Which temperature of water would dissolve the hot chocolate the quickest?

The girls made their prediction (they chose hot) and then it was time to experiment.

We started by emptying our hot chocolate packets into our mugs, one packet per mug. Then we moved on to testing the different temperatures of water.

We tested each temperature, one at a time. We were very vague with our temperatures, using ice cold water, room temperature water, and hot water. You can always add a kitchen thermometer to measure the temperature of the water to add an extra measurement element to your experiment.

My girls took turns measuring the water, stirring, and operating the stopwatch. We used the digital stopwatch on my phone to time how long the hot chocolate took to dissolve.

For each cup, we measured 6 oz. of water. We used cold water from our refrigerator over ice, lukewarm water from the tap, and I did my grown-up duty and heated water in the microwave for the last mug.

Once the water was added to a mug, one girl started the stopwatch and the other started stirring. We stopped the stopwatch as soon as we saw the hot chocolate had dissolved.

Does Hot Chocolate Dissolve Faster in Hot Water or Cold Water?

We started with the ice cold water. My oldest daughter was in charge of the stirring. She stirred and stirred and stirred some more. It wouldn't dissolve. Eventually, we made the decision to stop after three minutes. You can see the results above. Disgusting!

We moved on to the room temperature water, which clocked in at 1 minute 38 seconds. And, then the hot water, which only took 28 seconds.

The results: hot water takes the least amount of time. We predicted that because the instructions said to use hot water when we made hot chocolate. (And, it's called hot chocolate after all...) But, now we know why we need to use hot water.

Why Does Hot Chocolate Powder Dissolve Faster in Hot Water?

Hot water has more energy than cold water. With more energy, the molecules in the water move faster breaking down the hot chocolate mix quicker.

Once we finished writing our results, we unceremoniously dumped the cold water hot chocolate sludge down the kitchen sink. Ick.

What happened to the other two mugs? They were topped with a dollop of whipped cream and enjoyed!

Our hot chocolate science experiment and turned out great!

More STEAM Activities to Try
Hockey Science Christmas Science: Grow the Grinch's Heart Edible STEM Projects for Kids Marshmallow Engineering STEAM Building Challenge 28 Awesome STEM Challenges for the Elementary Classroom at Teach Junkie
STEM Activities for Kids in the Kitchen at iGame Mom

Do more science at home:

We love Green Kid Crafts boxes because they provide easy, ready-to-do STEM activities we can try at home. You'll receive easy-to-follow instructions plus the supplies that you need for up to 6 activities. You can get a monthly subscription or buy a single themed box. If you enjoyed our hot chocolate science experiment, you may enjoy the Kitchen Science or the monthly Discovery Box subscription.

Click here for the Kitchen Science box.

Click here for the monthly Discovery Box subscription.

Are you looking for more activities?

Join our fun Facebook community, Creative Family Fun for Busy Families, for daily activities that are great for kids and families. We'll chat, share, and have fun. It's a safe and private place to share idea for family and kids activities. I'd love for you to join me! Just click the link below, request to join, and answer the questions (they're easy, I promise). Come join the fun! Join the Creative Family Fun for Busy Families community here.

The following two tabs change content below.

# data[].attributes.attachment_link.description
This hot chocolate science experiment is a fun way to learn about how temperature affects the rate at which hot chocolate dissolves.

# data[].attributes.body
I chose this lesson because of the easy, fun, and active way for young children to show that they know their shapes. Students won’t even realize that they are doing math when it’s this fun!

- Kaylee Garman

# data[].attributes.attachment_link.readable_text
I've wanted to do a photo scavenger hunt with the kids for a long, long time. I always love any kind of scavenger hunt. And the boys love taking photos.

But the boys don't have their own camera, and all I have is my DSLR that I use (affiliate link) and I don't want to hand that over to the boys (I'm nervous of it breaking... and I couldn't go without it until I got it replaced).

I finally realized that the iPad mini (affiliate link) that we have can be used! Duh! It took me forever to come up with this solution.

Even better, it let me put the photo scavenger hunt right on the iPad for the kids to search for and then have George take photos of what he found.

I decided to hunt around the yard to find different shapes of objects. A square, circle, triangle and rectangle.

Triangles were the hardest to find, but found them in spokes of the cars and bikes.

Squares I found in our porch railing and skirting.

Circles were everywhere! I found a bell on their bikes, the ends of hoses, wheels of the million toys we have.

I took about a dozen photos of shapes I found around the yard and stored them in an album on the iPad for George.

George then took the iPad around the yard to find those shapes.

Once he found it, he switched over to the camera app to snap a photo of it too.

I have a collection of both my photos and his photos and its fun to compare the two!

Below is my photo for the triangle (I didn't have the red triangle and text in the photos, I just added that for this post to be clear).

And below is the photo that George took of the triangles he found.

He got the shape and object in every photo. But definitely not the same photo!

Below is my rectangle photo of a brick on the side of our house.

And below is George's version of the rectangle.

He didn't crop up nearly as close (maybe because I've told him time and time again to stay out of my plant beds and he's finally learning to listen).

This is the photo I took of the circle, a bell on his bike.

George tried to get it just the same! He did awesome hunting for them and finding the shapes!

This is his photo of the circle bell.

This photo scavenger hunt for the kids wasn't nearly as daunting as I thought it would be to put together. It took all of five minutes for me to walk around and find the shapes and snap the photos.

George loves anything to do with technology, so using the iPad to go on the scavenger hunt was a winner. Plus he got to take photos which he loves to do with it.

Got a hunter? The kids will love to go on any of these 32 ideas for scavenger hunts!

And in the meantime, he practiced his shapes. Triangles are still tough for him, but he's got squares and rectangles down now!

More move and learn ideas:

# data[].attributes.attachment_link.title
Photo Scavenger Hunt for Kids to Find Shapes

# data[].attributes.attachment_link.description
I've wanted to do a photo scavenger hunt with the kids for a long, long time. I always love any kind of scavenger hunt. And the boys love taking photos. But the boys don't have their own camera, and all I have is my DSLR that I use (affiliate link) and I don't want to hand that over to the boys (I'm nervous of it breaking...

# data[].attributes.body
#2 Jelly Bean Science

# data[].attributes.body
I chose this lesson because I like the use of ScratchJr. I also liked that this included an in depth lesson plan with the learning objectives and vocabulary used. It is a good way to incorporate technology while learning about animals.
-Avery

# data[].attributes.attachment_link.title
Creature Powers: Lesson Plan | PBS KIDS ScratchJr | PBS LearningMedia

# data[].attributes.attachment_link.description
Animate animal traits with the WILD KRATTS!

# data[].attributes.body
Sara Kashatus
I would use this lesson in my own classroom because it seems fun and easy. It is a good way to get children engaged and interested in science. It is also a good way to introduce the topic of energy and heat and how it relates to the students' everyday lives.

# data[].attributes.attachment_link.readable_text
I love my girls' natural curiosity when it comes to science. So, when my daughter asked me "Can we do a hot chocolate science experiment?" I knew it was time to get creative.

Working together, we came up with an amazing STEM activity.

When we make instant hot chocolate, we dissolve the contents of the packet into hot water. We decided to find out if temperature affected the speed that it dissolves.

Let's get started!

Disclosure: There are Amazon Affiliate and other affiliate links in this article which means, at no additional cost to you, we could receive compensation for our recommendations. You can read our full disclosure policy on our Disclosure Page for more details.

Supplies Needed for Your Hot Chocolate Science Project

First we needed to gather our supplies. Luckily most of the items were already in our kitchen.

Here's what you'll need:

Three heat-proof mugs
Three packets of instant hot chocolate
Measuring cup
Water
Spoons
Stopwatch or timer
Notebook for recording your results.

How to Do Your Hot Chocolate Science Experiment

We started our experiment by making a prediction. Which temperature of water would dissolve the hot chocolate the quickest?

The girls made their prediction (they chose hot) and then it was time to experiment.

We started by emptying our hot chocolate packets into our mugs, one packet per mug. Then we moved on to testing the different temperatures of water.

We tested each temperature, one at a time. We were very vague with our temperatures, using ice cold water, room temperature water, and hot water. You can always add a kitchen thermometer to measure the temperature of the water to add an extra measurement element to your experiment.

My girls took turns measuring the water, stirring, and operating the stopwatch. We used the digital stopwatch on my phone to time how long the hot chocolate took to dissolve.

For each cup, we measured 6 oz. of water. We used cold water from our refrigerator over ice, lukewarm water from the tap, and I did my grown-up duty and heated water in the microwave for the last mug.

Once the water was added to a mug, one girl started the stopwatch and the other started stirring. We stopped the stopwatch as soon as we saw the hot chocolate had dissolved.

Does Hot Chocolate Dissolve Faster in Hot Water or Cold Water?

We started with the ice cold water. My oldest daughter was in charge of the stirring. She stirred and stirred and stirred some more. It wouldn't dissolve. Eventually, we made the decision to stop after three minutes. You can see the results above. Disgusting!

We moved on to the room temperature water, which clocked in at 1 minute 38 seconds. And, then the hot water, which only took 28 seconds.

The results: hot water takes the least amount of time. We predicted that because the instructions said to use hot water when we made hot chocolate. (And, it's called hot chocolate after all...) But, now we know why we need to use hot water.

Why Does Hot Chocolate Powder Dissolve Faster in Hot Water?

Hot water has more energy than cold water. With more energy, the molecules in the water move faster breaking down the hot chocolate mix quicker.

Once we finished writing our results, we unceremoniously dumped the cold water hot chocolate sludge down the kitchen sink. Ick.

What happened to the other two mugs? They were topped with a dollop of whipped cream and enjoyed!

Our hot chocolate science experiment and turned out great!

More STEAM Activities to Try
Hockey Science Christmas Science: Grow the Grinch's Heart Edible STEM Projects for Kids Marshmallow Engineering STEAM Building Challenge 28 Awesome STEM Challenges for the Elementary Classroom at Teach Junkie
STEM Activities for Kids in the Kitchen at iGame Mom

Do more science at home:

We love Green Kid Crafts boxes because they provide easy, ready-to-do STEM activities we can try at home. You'll receive easy-to-follow instructions plus the supplies that you need for up to 6 activities. You can get a monthly subscription or buy a single themed box. If you enjoyed our hot chocolate science experiment, you may enjoy the Kitchen Science or the monthly Discovery Box subscription.

Click here for the Kitchen Science box.

Click here for the monthly Discovery Box subscription.

Are you looking for more activities?

Join our fun Facebook community, Creative Family Fun for Busy Families, for daily activities that are great for kids and families. We'll chat, share, and have fun. It's a safe and private place to share idea for family and kids activities. I'd love for you to join me! Just click the link below, request to join, and answer the questions (they're easy, I promise). Come join the fun! Join the Creative Family Fun for Busy Families community here.

The following two tabs change content below.

# data[].attributes.attachment_link.description
This hot chocolate science experiment is a fun way to learn about how temperature affects the rate at which hot chocolate dissolves.

# data[].attributes.body
Accidentally commented instead.
Here's the link

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What's cheaper than a Peep? Jelly beans! They're everywhere and after Easter, stores mark them half off. I have 3 Easter science activities to share with you today that are awesome for your elementary students. Keep it simple or take them to the next level!

Solubility

The first activity addresses solutions, solutes, solvents, and concentration. There are several ways you can do this, but here is one of them.
Use different amounts of warm water (100ml and 25ml) to dissolve 2 jelly bean candy shells. (A little white part will remain that you can toss.) You can use *strong* baggies or cups for the water. Identify how the transparency of the color depends on the concentration.

Physical Properties

Identify the physical properties of a jelly bean. Mix them together in a group. Do the physical properties of the jelly bean change? Place the jelly bean in water. How do the physical properties of the jelly bean change?

Jelly Bean Towers

Provide each student with 10 toothpicks and 10 jelly beans. The challenge to create the tallest stable tower possible. There must be a jelly bean at the top of the tower. Identify weak levels and strong levels. Provide students an opportunity to draw their designs and refine them.

Happy Easter!

# data[].attributes.attachment_link.title
Easter Science Activities with Jelly Beans

# data[].attributes.attachment_link.description
What's cheaper than a Peep? Jelly beans! They're everywhere and after Easter, stores mark them half off. I have 3 Easter science activities to share with you today that are awesome for your elementary students. Keep it simple or take them to the next level! The first activity addresses solutions, solutes, solvents, and concentration.

# data[].attributes.body
This is a great physical activity, that can be adjusted for any age group. For a day that children are squirming or a planned lesson, this gets students working as a team, excited, and competitive. -Deborah

# data[].attributes.attachment_link.readable_text
I've wanted to do a photo scavenger hunt with the kids for a long, long time. I always love any kind of scavenger hunt. And the boys love taking photos.

But the boys don't have their own camera, and all I have is my DSLR that I use (affiliate link) and I don't want to hand that over to the boys (I'm nervous of it breaking... and I couldn't go without it until I got it replaced).

I finally realized that the iPad mini (affiliate link) that we have can be used! Duh! It took me forever to come up with this solution.

Even better, it let me put the photo scavenger hunt right on the iPad for the kids to search for and then have George take photos of what he found.

I decided to hunt around the yard to find different shapes of objects. A square, circle, triangle and rectangle.

Triangles were the hardest to find, but found them in spokes of the cars and bikes.

Squares I found in our porch railing and skirting.

Circles were everywhere! I found a bell on their bikes, the ends of hoses, wheels of the million toys we have.

I took about a dozen photos of shapes I found around the yard and stored them in an album on the iPad for George.

George then took the iPad around the yard to find those shapes.

Once he found it, he switched over to the camera app to snap a photo of it too.

I have a collection of both my photos and his photos and its fun to compare the two!

Below is my photo for the triangle (I didn't have the red triangle and text in the photos, I just added that for this post to be clear).

And below is the photo that George took of the triangles he found.

He got the shape and object in every photo. But definitely not the same photo!

Below is my rectangle photo of a brick on the side of our house.

And below is George's version of the rectangle.

He didn't crop up nearly as close (maybe because I've told him time and time again to stay out of my plant beds and he's finally learning to listen).

This is the photo I took of the circle, a bell on his bike.

George tried to get it just the same! He did awesome hunting for them and finding the shapes!

This is his photo of the circle bell.

This photo scavenger hunt for the kids wasn't nearly as daunting as I thought it would be to put together. It took all of five minutes for me to walk around and find the shapes and snap the photos.

George loves anything to do with technology, so using the iPad to go on the scavenger hunt was a winner. Plus he got to take photos which he loves to do with it.

Got a hunter? The kids will love to go on any of these 32 ideas for scavenger hunts!

And in the meantime, he practiced his shapes. Triangles are still tough for him, but he's got squares and rectangles down now!

More move and learn ideas:

# data[].attributes.attachment_link.title
Photo Scavenger Hunt for Kids to Find Shapes

# data[].attributes.attachment_link.description
I've wanted to do a photo scavenger hunt with the kids for a long, long time. I always love any kind of scavenger hunt. And the boys love taking photos. But the boys don't have their own camera, and all I have is my DSLR that I use (affiliate link) and I don't want to hand that over to the boys (I'm nervous of it breaking...

# data[].attributes.body
I chose this lesson out of the two because I think this lesson will interest the children and it will also allow them to have time to be independent. It also is a fun way to challenge the students to think and hunt for different shapes/objects and it hits many different 21st Century Skills

# data[].attributes.attachment_link.readable_text
I've wanted to do a photo scavenger hunt with the kids for a long, long time. I always love any kind of scavenger hunt. And the boys love taking photos.

But the boys don't have their own camera, and all I have is my DSLR that I use (affiliate link) and I don't want to hand that over to the boys (I'm nervous of it breaking... and I couldn't go without it until I got it replaced).

I finally realized that the iPad mini (affiliate link) that we have can be used! Duh! It took me forever to come up with this solution.

Even better, it let me put the photo scavenger hunt right on the iPad for the kids to search for and then have George take photos of what he found.

I decided to hunt around the yard to find different shapes of objects. A square, circle, triangle and rectangle.

Triangles were the hardest to find, but found them in spokes of the cars and bikes.

Squares I found in our porch railing and skirting.

Circles were everywhere! I found a bell on their bikes, the ends of hoses, wheels of the million toys we have.

I took about a dozen photos of shapes I found around the yard and stored them in an album on the iPad for George.

George then took the iPad around the yard to find those shapes.

Once he found it, he switched over to the camera app to snap a photo of it too.

I have a collection of both my photos and his photos and its fun to compare the two!

Below is my photo for the triangle (I didn't have the red triangle and text in the photos, I just added that for this post to be clear).

And below is the photo that George took of the triangles he found.

He got the shape and object in every photo. But definitely not the same photo!

Below is my rectangle photo of a brick on the side of our house.

And below is George's version of the rectangle.

He didn't crop up nearly as close (maybe because I've told him time and time again to stay out of my plant beds and he's finally learning to listen).

This is the photo I took of the circle, a bell on his bike.

George tried to get it just the same! He did awesome hunting for them and finding the shapes!

This is his photo of the circle bell.

This photo scavenger hunt for the kids wasn't nearly as daunting as I thought it would be to put together. It took all of five minutes for me to walk around and find the shapes and snap the photos.

George loves anything to do with technology, so using the iPad to go on the scavenger hunt was a winner. Plus he got to take photos which he loves to do with it.

Got a hunter? The kids will love to go on any of these 32 ideas for scavenger hunts!

And in the meantime, he practiced his shapes. Triangles are still tough for him, but he's got squares and rectangles down now!

More move and learn ideas:

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Photo Scavenger Hunt for Kids to Find Shapes

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I've wanted to do a photo scavenger hunt with the kids for a long, long time. I always love any kind of scavenger hunt. And the boys love taking photos. But the boys don't have their own camera, and all I have is my DSLR that I use (affiliate link) and I don't want to hand that over to the boys (I'm nervous of it breaking...

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Sara Kashatus
I would choose this lesson because it is so easy to change it for whatever grade you are teaching. I also love the technology that it uses in the lesson and the skills that it helps the students develop. I also love how thorough the lesson is and the materials that PBS includes.

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Creature Powers: Lesson Plan | PBS KIDS ScratchJr | PBS LearningMedia

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Animate animal traits with the WILD KRATTS!

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I would use this lesson because of all of the standards met and the 21st Century Skills learned. The lesson overall seems like it would take a while to do, but once looking deeper into it, I think students would find it interesting.

- Kaylee Garman

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Quick Look

Grade Level: 4 (3-5)

Time Required: 45 minutes

Expendable Cost/Group: US $2.00

Group Size: 3

Activity Dependency: None

Subject Areas: Physical Science, Science and Technology

NGSS Performance Expectations:

Summary Students use potatoes to light an LED clock (or light bulb) as they learn how a battery works in a simple circuit and how chemical energy changes to electrical energy. As they learn more about electrical energy, they better understand the concepts of voltage, current and resistance.
This engineering curriculum aligns to Next Generation Science Standards (NGSS).

Engineering Connection

Engineers use batteries to store energy in a wide range of situations. A solid electrolyte battery is most suitable in very extreme weather conditions, while nickel-zinc batteries work best in electric vehicles. Energy engineers continually evolve technology to improve the performance and life-cycle costs of batteries that store solar and wind energy. When designing a battery, engineers keep in mind the needs of the application, and use different substances to create current flow. They consider characteristics such as power output, ability to recharge, reliability, size, safety, heat generation, length of life cycle, abuse tolerance, cost and ability to be recycled. Isn't the power of engineering creativity amazing?

Learning Objectives

After this activity, students should be able to:

Describe the flow of electrical energy through a simple circuit.

Explain why a light bulb may take more than one battery to light up.

Explain the role of electrical engineers in the development of electricity sources and the products that use electricity.

Educational Standards

Each TeachEngineering lesson or activity is correlated to one or more K-12 science, technology, engineering or math (STEM) educational standards.

All 100,000+ K-12 STEM standards covered in TeachEngineering are collected, maintained and packaged by the Achievement Standards Network (ASN), a project of D2L (www.achievementstandards.org).

In the ASN, standards are hierarchically structured: first by source; e.g., by state; within source by type; e.g., science or mathematics; within type by subtype, then by grade, etc.

NGSS Performance Expectation

Click to view other curriculum aligned to this Performance Expectation

This activity focuses on the following Three Dimensional Learning aspects of NGSS:

Science & Engineering Practices

Disciplinary Core Ideas

Crosscutting Concepts

Make observations to produce data to serve as the basis for evidence for an explanation of a phenomenon or test a design solution.

Energy can be moved from place to place by moving objects or through sound, light, or electric currents. Energy is present whenever there are moving objects, sound, light, or heat. When objects collide, energy can be transferred from one object to another, thereby changing their motion. In such collisions, some energy is typically also transferred to the surrounding air; as a result, the air gets heated and sound is produced. Light also transfers energy from place to place. Energy can also be transferred from place to place by electric currents, which can then be used locally to produce motion, sound, heat, or light. The currents may have been produced to begin with by transforming the energy of motion into electrical energy.

Energy can be transferred in various ways and between objects.

Suggest an alignment not listed above

Materials List

To make a potato battery, each group needs:

3 copper pennies (or copper strips), one per potato

3 zinc nails; these are galvanized nails, available at hardware stores

5 insulated wires, 15-20 cm (6-8 inches) long, with alligator clips at the ends

1 low-current, light emitting diode (LED) clock (or LCD clock) requiring ~1.5 volts (or a small LED)

OR above materials can be purchased cumulatively in a kit, available online

For the entire class to share or one per team:

(optional) multimeter(s) or voltmeter(s); a multimeter measures current, voltage and resistance of a circuit; available at Radio Shack or other electronics stores or websites

Worksheets and Attachments
Visit [www.teachengineering.org/activities/view/cub_energy2_lesson04_activity2] to print or download.

Introduction/Motivation

What is electrical energy? From where does it come? Can you think of anything that needs electrical energy to work? How about lamps, music players, TVs and ovens? How do we get the power to run these devices? What role do electrical engineers play in improving our lives?

One place we can find electrical energy in our homes is at a wall outlet. So, how does electrical energy reach the wall outlet in our house? The energy comes from an electrical power plant, which usually makes electrical energy from burning fossil fuels, such as coal and oil. The heat energy from the burning fuel heats up water. When the water boils, it becomes steam, which flows through a pipe into a turbine (a wheel with blades). As the turbine spins from the steam, it turns a generator (a spinning magnet) that unbalances the charges in nearby atoms and produces a current of electricity. The electrical current flows through protected wires to our house.

How else can we power electrical appliances? That's right, from a battery. A battery works by providing electrons with a solution in which they can move around. Have you ever noticed that some batteries have a copper end that is positive (shown with a plus [+] sign) and another end that is negative (shown with a minus [-] sign)? Zinc is a metal that likes to give its electrons to copper. Usually, zinc just gives its electrons to copper and then the process stops. However, if you provide the electrons with a solution (called an electrolyte) to help them move to the copper, and you give the electrons a wire in which they can move from the copper back to the zinc, you can produce a circuit and a flowing path of electrical energy. (Note: Conventional current flows from positive to negative, so from the copper, through the wire, back to the zinc. The electrons actually flow negative to positive.)

A circuit is a complete path of electrical energy. This means that electrical energy or charge is produced or stored somewhere ( voltage) and has a path for the charge to flow (or current). Another part of a circuit is a resistance, such as a light bulb. Electrical engineers create circuits to help electrical energy perform work, such as lighting a room or keeping food cold. An appliance, light bulb or almost any device that uses electrical energy is a resistance. A resistance prevents or slows an electrical current or charge from moving. When electrical current flows through a source of resistance, it can be changed into light or heat or sound. Even though you cannot see it, the light bulb or appliance slows down the electrical charge.

Electrical engineers help develop the many modern products and appliances that require electrical energy. Electrical engineers also help create the technology used to generate the electrical energy in power plants in the first place. These engineers know a lot about circuits and they continually work to find better ways to store electrical charge and generate electrical current without using nonrenewable fossil fuels such as coal and oil. These electrical engineers are very important in almost everything we do! Essentially, electrical engineers create improvements for society and help save our planet for future generations. Today, we are going to be electrical engineers and learn more about how electrical energy works in a circuit. We are also going to look at generating electrical current from the energy stored in a potato! Do you think we can light a bulb with a potato? Let's try it!

Procedure

Background

How does a potato battery work? The copper (Cu) atoms attract electrons more than the zinc (Zn) atoms. If you place a strip of copper and a strip of zinc in contact with each other, many electrons pass from the zinc to the copper. As they concentrate on the copper, the electrons repel each other. When the force of repulsion between electrons and the force of attraction of electrons to the copper become equalized, the flow of electrons stops. Unfortunately it is not possible to take advantage of this behavior to produce electricity because the flow of charges stops almost immediately. On the other hand, if you bathe the two strips in a conductive solution, and connect them externally with a wire, the reactions between the electrodes and the solution continually furnish the circuit with charges. In this way, the process that produces the electrical energy continues and becomes useful. In a conductive solution, the charge is carried by ions that move through the solution. In the solid state, the ions are not able to move around freely. However, once they are dissolved in water, they become completely mobile. They can "swim" around in the water and thus can respond to an electric current from a battery. That current supplies electrons that cause positive ions to flow in one direction and negative ions to flow in the opposite direction. The ions carry electrical charge from one electrode to another, completing the electrical circuit.

For a conductive solution, use any electrolyte, whether it is an acid, base or salt solution. An electrolyte is a substance whose aqueous solution contains various ions and thus conducts electricity. Therefore, the more free ions a solution has, the better conductor it will be. Many fruits and vegetables contain juices rich in ions and are therefore good electrical conductors.

Like any battery, a potato battery has a limited life span. The electrodes undergo chemical reactions that block the flow of electricity. The electromotive force diminishes and the battery stops working. Usually, what happens is the production of hydrogen at the copper electrode and the zinc electrode acquires deposits of oxides that act as a barrier between the metal and the electrolyte. This is referred to as the electrodes being polarized. To achieve a longer life and higher voltages and current flows, it is necessary to use electrolytes better suited for the purpose. Commercial batteries, apart from their normal electrolyte, contain chemicals with an affinity for hydrogen, which combine with the hydrogen before it can polarize the electrodes.

Before the Activity

With the Students

1. Divide the class into teams of two or three students each. Hand out the materials.

2. Direct groups to carefully place the zinc nails and copper pennies into the potato. Make sure the two different metals do not touch each other in the potato (see Figure 1).

3. Connect one alligator clip to the end of the penny sticking out of the potato and another alligator clip to the end of the nail sticking out of the potato (see Figure 1).

Figure 1. Placement of the nail, penny and alligator clips.

1. (If you have a multimeter) Tell students that a multimeter is an instrument that measures current, voltage and resistance of a circuit, and is a tool (created by and) often used by engineers. Set the multimeter on a low "DC volts" scale for voltage and "DC milliamps" for current, so students can see the charge that one potato can produce. Expect the potato to produce just less than 1 volt. Encourage students to convert the decimal readout from the multimeter to a fraction (for example, 0.82 volts = 82/100 volts).

2. Have the students figure out how many potatoes they need to light their LED clock (or clock). For example, if their potato produces a voltage of 0.8 volts, then they may need two potatoes to power a 1.5 voltage LED.

3. Have students experiment to figure out how to connect two potatoes together. To connect two potatoes in series (to add more voltage), place a penny and nail into a second potato, and connect the wire from the zinc nail in the first potato to the copper penny in the second. Then, add a third wire to the zinc nail in the second potato. Always remember to connect the copper (positive) end of the potato (battery) to the zinc (negative) end of the next potato (see Figure 2).

Figure 2. Activity setup to create a potato battery to power an LED clock.

1. Expect two potatoes in series to be able to light an LED; however, you might need three. Show students how to connect the LEDs to the potato in the correct manner, that is, the positive end of the LED to the negative end of the potato battery (zinc nail) and the negative end of the LED to the positive end of the potato battery (copper penny).

2. Have students discuss how the potatoes provide the electrolyte (solution) for the chemical battery to work. Ask for suggestions of other foods we could try (for example, lemons, berries, apples).

3. Ask students to complete the worksheet either individually or in pairs. After they finish, have them compare answers with a peer or another pair, giving all students time to finish.

Vocabulary/Definitions

conductor: An object that allows the transfer of electrons.

current: The movement of electrons.

electrical energy: Energy produced through the movement of electrons (voltage X current).

electrolyte: A solution that conducts electricity.

energy: The ability to do work.

insulator: An object that inhibits the transfer of electrons.

resistance: Objects or substances that prevent the passage of a steady electric current.

voltage: The amount of energy produced.

Assessment

Pre-Activity Assessment

Brainstorming: In small groups, have students engage in open discussion. Remind them that no idea or suggestion is "silly." All ideas should be respectfully heard. Take an uncritical position, encourage wild ideas and discourage criticism of ideas. Ask students how many items they can think of that run on batteries. As a class, record their ideas on the board.

Quick Poll: Before the activity begins, ask the class a question and tally their responses on the board. Ask: Can we get electrical energy from a fruit or vegetable?

Activity Embedded Assessment

Worksheet /Pairs Check: Have students work individually or in pairs on the Make a Battery Worksheet. After they finish, have them compare answers with a peer or another pair, giving all students time to finish the worksheet.

Hypothesize: Ask each group what would happen if we added more potatoes in a row to our circuits? (Answer: Adding more potatoes in a row is the same as adding batteries in a row. The voltage of each piece of potato is added up. Thus, the voltage of our circuit would increase. On the other hand, the current of our circuit would not increase. Current is not dependent on how many potatoes but is related to the size of each potato individually.)

Post-Activity Assessment

Problem Solving: Present the class with the following math problems and ask students to calculate how many of each vegetable or fruit are needed to light the bulb.

If a lemon produces 1 Volt of energy, how many lemons would you need to light a 2 Volt light bulb? (Answer: 2)

If a potato produces 0.8 Volts of energy, how many potatoes would you need to light a 1.5 Volt light bulb? (Answer: 2)

If a potato produces 0.8 Volts of energy, how many potatoes would you need to light a 3 Volt digital clock? (Answer: 4)

If you have a lemon that produces 1 Volt of energy and an apple that produces 1 Volt of energy, can you light a 3 Volt clock? (Answer: No, you would need one more lemon or apple.)

Diagramming: Engineers must understand how circuits work in order to develop cool new technologies. Draw a picture of your potato battery. Label the battery (voltage) and the resistance (light bulb). Draw an arrow to show the current flow (from the copper end to the zinc end). List two cool products that an engineer could develop that run off a fruit battery.

Troubleshooting Tips

If the LED clock, light or small light bulbs do not work, check the setup of the potato battery. Perhaps the ends are not all connected from negative to positive, or perhaps there is not enough potato voltage. Check the voltage of the potato using a multimeter or voltmeter. Another possibility is having enough voltage, but not enough current to light the bulb, which is why it is recommended to use only very low-volt LED clocks or bulbs. Also, try using more potatoes (i.e., 5 potato halves) to strengthen conductivity. Try different LED colors (for example, the blue LED may work better than the red).

Lemons and oranges also work well for this activity. They work best if you first roll them on a table top, which breaks down the cells inside so more juice flows through the fruit (current).

Some people have more conduction success using copper strips instead of copper pennies (can also wrap the pennies in copper ribbon).

Soaking the potatoes in Gatorade overnight can make them more conductive.

Activity Extensions

At activity end, before students disassemble their potato batteries, it is fun to have the entire class connect their fruit batteries in series, making "a serious tater circle."

Have students try the activity again using different fruits or vegetables! Many fruits and vegetables work, such as lemons, limes, apples and carrots. Have students compare and contrast the performance of different fruits and vegetables.

Have students complete the activity again using an electrolyte solution, such as salt water or vinegar. Have them compare and contrast the performance of different electrolyte solutions.

To add a math component, have students use the multimeter to compare the flow of electricity for several different fruits as well as to the total amount of fruits used. Ask them to graph the results and hypothesize what is happening.

Activity Scaling

Have more advanced students experiment with parallel and series configurations using different numbers of potatoes.

References

Dictionary.com. Lexico Publishing Group, LLC. Accessed September 28, 2005. (Source of some vocabulary definitions, with some adaptation) http://www.dictionary.com

Phillips, W.D. Chapter 2P: Using a Multimeter. Design Electronics (online textbook) DOCTRONICS Educational Publishing, UK. Accessed September 28, 2005. (Good design, technology and electronics resources.) http://www.doctronics.co.uk/meter.htm

Copyright © 2005 by Regents of the University of Colorado

Contributors Sharon D. Perez-Suarez; Jeff Lyng; Malinda Schaefer Zarske; Denise W. Carlson; Janet Yowell

Supporting Program Integrated Teaching and Learning Program, College of Engineering, University of Colorado Boulder

Acknowledgements

The contents of this digital library curriculum were developed under grants from the Fund for the Improvement of Postsecondary Education (FIPSE), U.S. Department of Education, and the National Science Foundation (GK-12 grant no. 0338326). However, these contents do not necessarily represent the policies of the Department of Education or National Science Foundation, and you should not assume endorsement by the federal government.

Last modified: July 9, 2020

# data[].attributes.attachment_link.description
Students use potatoes to light an LED clock (or light bulb) as they learn how a battery works in a simple circuit and how chemical energy changes to electrical energy. As they learn more about electrical energy, they better understand the concepts of voltage, current and resistance.

# data[].attributes.body
I liked this lesson over the other because it is a fun and different activity that students will enjoy and have fun with. While there are quite a few steps and materials that need to be used, students will surely remember the lesson and what they learned from it. It also covered so many 21st century skills and ISTE standards.
-Avery

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Quick Look

Grade Level: 4 (3-5)

Time Required: 45 minutes

Expendable Cost/Group: US $2.00

Group Size: 3

Activity Dependency: None

Subject Areas: Physical Science, Science and Technology

NGSS Performance Expectations:

Summary Students use potatoes to light an LED clock (or light bulb) as they learn how a battery works in a simple circuit and how chemical energy changes to electrical energy. As they learn more about electrical energy, they better understand the concepts of voltage, current and resistance.
This engineering curriculum aligns to Next Generation Science Standards (NGSS).

Engineering Connection

Engineers use batteries to store energy in a wide range of situations. A solid electrolyte battery is most suitable in very extreme weather conditions, while nickel-zinc batteries work best in electric vehicles. Energy engineers continually evolve technology to improve the performance and life-cycle costs of batteries that store solar and wind energy. When designing a battery, engineers keep in mind the needs of the application, and use different substances to create current flow. They consider characteristics such as power output, ability to recharge, reliability, size, safety, heat generation, length of life cycle, abuse tolerance, cost and ability to be recycled. Isn't the power of engineering creativity amazing?

Learning Objectives

After this activity, students should be able to:

Describe the flow of electrical energy through a simple circuit.

Explain why a light bulb may take more than one battery to light up.

Explain the role of electrical engineers in the development of electricity sources and the products that use electricity.

Educational Standards

Each TeachEngineering lesson or activity is correlated to one or more K-12 science, technology, engineering or math (STEM) educational standards.

All 100,000+ K-12 STEM standards covered in TeachEngineering are collected, maintained and packaged by the Achievement Standards Network (ASN), a project of D2L (www.achievementstandards.org).

In the ASN, standards are hierarchically structured: first by source; e.g., by state; within source by type; e.g., science or mathematics; within type by subtype, then by grade, etc.

NGSS Performance Expectation

Click to view other curriculum aligned to this Performance Expectation

This activity focuses on the following Three Dimensional Learning aspects of NGSS:

Science & Engineering Practices

Disciplinary Core Ideas

Crosscutting Concepts

Make observations to produce data to serve as the basis for evidence for an explanation of a phenomenon or test a design solution.

Energy can be moved from place to place by moving objects or through sound, light, or electric currents. Energy is present whenever there are moving objects, sound, light, or heat. When objects collide, energy can be transferred from one object to another, thereby changing their motion. In such collisions, some energy is typically also transferred to the surrounding air; as a result, the air gets heated and sound is produced. Light also transfers energy from place to place. Energy can also be transferred from place to place by electric currents, which can then be used locally to produce motion, sound, heat, or light. The currents may have been produced to begin with by transforming the energy of motion into electrical energy.

Energy can be transferred in various ways and between objects.

Suggest an alignment not listed above

Materials List

To make a potato battery, each group needs:

3 copper pennies (or copper strips), one per potato

3 zinc nails; these are galvanized nails, available at hardware stores

5 insulated wires, 15-20 cm (6-8 inches) long, with alligator clips at the ends

1 low-current, light emitting diode (LED) clock (or LCD clock) requiring ~1.5 volts (or a small LED)

OR above materials can be purchased cumulatively in a kit, available online

For the entire class to share or one per team:

(optional) multimeter(s) or voltmeter(s); a multimeter measures current, voltage and resistance of a circuit; available at Radio Shack or other electronics stores or websites

Worksheets and Attachments
Visit [www.teachengineering.org/activities/view/cub_energy2_lesson04_activity2] to print or download.

Introduction/Motivation

What is electrical energy? From where does it come? Can you think of anything that needs electrical energy to work? How about lamps, music players, TVs and ovens? How do we get the power to run these devices? What role do electrical engineers play in improving our lives?

One place we can find electrical energy in our homes is at a wall outlet. So, how does electrical energy reach the wall outlet in our house? The energy comes from an electrical power plant, which usually makes electrical energy from burning fossil fuels, such as coal and oil. The heat energy from the burning fuel heats up water. When the water boils, it becomes steam, which flows through a pipe into a turbine (a wheel with blades). As the turbine spins from the steam, it turns a generator (a spinning magnet) that unbalances the charges in nearby atoms and produces a current of electricity. The electrical current flows through protected wires to our house.

How else can we power electrical appliances? That's right, from a battery. A battery works by providing electrons with a solution in which they can move around. Have you ever noticed that some batteries have a copper end that is positive (shown with a plus [+] sign) and another end that is negative (shown with a minus [-] sign)? Zinc is a metal that likes to give its electrons to copper. Usually, zinc just gives its electrons to copper and then the process stops. However, if you provide the electrons with a solution (called an electrolyte) to help them move to the copper, and you give the electrons a wire in which they can move from the copper back to the zinc, you can produce a circuit and a flowing path of electrical energy. (Note: Conventional current flows from positive to negative, so from the copper, through the wire, back to the zinc. The electrons actually flow negative to positive.)

A circuit is a complete path of electrical energy. This means that electrical energy or charge is produced or stored somewhere ( voltage) and has a path for the charge to flow (or current). Another part of a circuit is a resistance, such as a light bulb. Electrical engineers create circuits to help electrical energy perform work, such as lighting a room or keeping food cold. An appliance, light bulb or almost any device that uses electrical energy is a resistance. A resistance prevents or slows an electrical current or charge from moving. When electrical current flows through a source of resistance, it can be changed into light or heat or sound. Even though you cannot see it, the light bulb or appliance slows down the electrical charge.

Electrical engineers help develop the many modern products and appliances that require electrical energy. Electrical engineers also help create the technology used to generate the electrical energy in power plants in the first place. These engineers know a lot about circuits and they continually work to find better ways to store electrical charge and generate electrical current without using nonrenewable fossil fuels such as coal and oil. These electrical engineers are very important in almost everything we do! Essentially, electrical engineers create improvements for society and help save our planet for future generations. Today, we are going to be electrical engineers and learn more about how electrical energy works in a circuit. We are also going to look at generating electrical current from the energy stored in a potato! Do you think we can light a bulb with a potato? Let's try it!

Procedure

Background

How does a potato battery work? The copper (Cu) atoms attract electrons more than the zinc (Zn) atoms. If you place a strip of copper and a strip of zinc in contact with each other, many electrons pass from the zinc to the copper. As they concentrate on the copper, the electrons repel each other. When the force of repulsion between electrons and the force of attraction of electrons to the copper become equalized, the flow of electrons stops. Unfortunately it is not possible to take advantage of this behavior to produce electricity because the flow of charges stops almost immediately. On the other hand, if you bathe the two strips in a conductive solution, and connect them externally with a wire, the reactions between the electrodes and the solution continually furnish the circuit with charges. In this way, the process that produces the electrical energy continues and becomes useful. In a conductive solution, the charge is carried by ions that move through the solution. In the solid state, the ions are not able to move around freely. However, once they are dissolved in water, they become completely mobile. They can "swim" around in the water and thus can respond to an electric current from a battery. That current supplies electrons that cause positive ions to flow in one direction and negative ions to flow in the opposite direction. The ions carry electrical charge from one electrode to another, completing the electrical circuit.

For a conductive solution, use any electrolyte, whether it is an acid, base or salt solution. An electrolyte is a substance whose aqueous solution contains various ions and thus conducts electricity. Therefore, the more free ions a solution has, the better conductor it will be. Many fruits and vegetables contain juices rich in ions and are therefore good electrical conductors.

Like any battery, a potato battery has a limited life span. The electrodes undergo chemical reactions that block the flow of electricity. The electromotive force diminishes and the battery stops working. Usually, what happens is the production of hydrogen at the copper electrode and the zinc electrode acquires deposits of oxides that act as a barrier between the metal and the electrolyte. This is referred to as the electrodes being polarized. To achieve a longer life and higher voltages and current flows, it is necessary to use electrolytes better suited for the purpose. Commercial batteries, apart from their normal electrolyte, contain chemicals with an affinity for hydrogen, which combine with the hydrogen before it can polarize the electrodes.

Before the Activity

With the Students

1. Divide the class into teams of two or three students each. Hand out the materials.

2. Direct groups to carefully place the zinc nails and copper pennies into the potato. Make sure the two different metals do not touch each other in the potato (see Figure 1).

3. Connect one alligator clip to the end of the penny sticking out of the potato and another alligator clip to the end of the nail sticking out of the potato (see Figure 1).

Figure 1. Placement of the nail, penny and alligator clips.

1. (If you have a multimeter) Tell students that a multimeter is an instrument that measures current, voltage and resistance of a circuit, and is a tool (created by and) often used by engineers. Set the multimeter on a low "DC volts" scale for voltage and "DC milliamps" for current, so students can see the charge that one potato can produce. Expect the potato to produce just less than 1 volt. Encourage students to convert the decimal readout from the multimeter to a fraction (for example, 0.82 volts = 82/100 volts).

2. Have the students figure out how many potatoes they need to light their LED clock (or clock). For example, if their potato produces a voltage of 0.8 volts, then they may need two potatoes to power a 1.5 voltage LED.

3. Have students experiment to figure out how to connect two potatoes together. To connect two potatoes in series (to add more voltage), place a penny and nail into a second potato, and connect the wire from the zinc nail in the first potato to the copper penny in the second. Then, add a third wire to the zinc nail in the second potato. Always remember to connect the copper (positive) end of the potato (battery) to the zinc (negative) end of the next potato (see Figure 2).

Figure 2. Activity setup to create a potato battery to power an LED clock.

1. Expect two potatoes in series to be able to light an LED; however, you might need three. Show students how to connect the LEDs to the potato in the correct manner, that is, the positive end of the LED to the negative end of the potato battery (zinc nail) and the negative end of the LED to the positive end of the potato battery (copper penny).

2. Have students discuss how the potatoes provide the electrolyte (solution) for the chemical battery to work. Ask for suggestions of other foods we could try (for example, lemons, berries, apples).

3. Ask students to complete the worksheet either individually or in pairs. After they finish, have them compare answers with a peer or another pair, giving all students time to finish.

Vocabulary/Definitions

conductor: An object that allows the transfer of electrons.

current: The movement of electrons.

electrical energy: Energy produced through the movement of electrons (voltage X current).

electrolyte: A solution that conducts electricity.

energy: The ability to do work.

insulator: An object that inhibits the transfer of electrons.

resistance: Objects or substances that prevent the passage of a steady electric current.

voltage: The amount of energy produced.

Assessment

Pre-Activity Assessment

Brainstorming: In small groups, have students engage in open discussion. Remind them that no idea or suggestion is "silly." All ideas should be respectfully heard. Take an uncritical position, encourage wild ideas and discourage criticism of ideas. Ask students how many items they can think of that run on batteries. As a class, record their ideas on the board.

Quick Poll: Before the activity begins, ask the class a question and tally their responses on the board. Ask: Can we get electrical energy from a fruit or vegetable?

Activity Embedded Assessment

Worksheet /Pairs Check: Have students work individually or in pairs on the Make a Battery Worksheet. After they finish, have them compare answers with a peer or another pair, giving all students time to finish the worksheet.

Hypothesize: Ask each group what would happen if we added more potatoes in a row to our circuits? (Answer: Adding more potatoes in a row is the same as adding batteries in a row. The voltage of each piece of potato is added up. Thus, the voltage of our circuit would increase. On the other hand, the current of our circuit would not increase. Current is not dependent on how many potatoes but is related to the size of each potato individually.)

Post-Activity Assessment

Problem Solving: Present the class with the following math problems and ask students to calculate how many of each vegetable or fruit are needed to light the bulb.

If a lemon produces 1 Volt of energy, how many lemons would you need to light a 2 Volt light bulb? (Answer: 2)

If a potato produces 0.8 Volts of energy, how many potatoes would you need to light a 1.5 Volt light bulb? (Answer: 2)

If a potato produces 0.8 Volts of energy, how many potatoes would you need to light a 3 Volt digital clock? (Answer: 4)

If you have a lemon that produces 1 Volt of energy and an apple that produces 1 Volt of energy, can you light a 3 Volt clock? (Answer: No, you would need one more lemon or apple.)

Diagramming: Engineers must understand how circuits work in order to develop cool new technologies. Draw a picture of your potato battery. Label the battery (voltage) and the resistance (light bulb). Draw an arrow to show the current flow (from the copper end to the zinc end). List two cool products that an engineer could develop that run off a fruit battery.

Troubleshooting Tips

If the LED clock, light or small light bulbs do not work, check the setup of the potato battery. Perhaps the ends are not all connected from negative to positive, or perhaps there is not enough potato voltage. Check the voltage of the potato using a multimeter or voltmeter. Another possibility is having enough voltage, but not enough current to light the bulb, which is why it is recommended to use only very low-volt LED clocks or bulbs. Also, try using more potatoes (i.e., 5 potato halves) to strengthen conductivity. Try different LED colors (for example, the blue LED may work better than the red).

Lemons and oranges also work well for this activity. They work best if you first roll them on a table top, which breaks down the cells inside so more juice flows through the fruit (current).

Some people have more conduction success using copper strips instead of copper pennies (can also wrap the pennies in copper ribbon).

Soaking the potatoes in Gatorade overnight can make them more conductive.

Activity Extensions

At activity end, before students disassemble their potato batteries, it is fun to have the entire class connect their fruit batteries in series, making "a serious tater circle."

Have students try the activity again using different fruits or vegetables! Many fruits and vegetables work, such as lemons, limes, apples and carrots. Have students compare and contrast the performance of different fruits and vegetables.

Have students complete the activity again using an electrolyte solution, such as salt water or vinegar. Have them compare and contrast the performance of different electrolyte solutions.

To add a math component, have students use the multimeter to compare the flow of electricity for several different fruits as well as to the total amount of fruits used. Ask them to graph the results and hypothesize what is happening.

Activity Scaling

Have more advanced students experiment with parallel and series configurations using different numbers of potatoes.

References

Dictionary.com. Lexico Publishing Group, LLC. Accessed September 28, 2005. (Source of some vocabulary definitions, with some adaptation) http://www.dictionary.com

Phillips, W.D. Chapter 2P: Using a Multimeter. Design Electronics (online textbook) DOCTRONICS Educational Publishing, UK. Accessed September 28, 2005. (Good design, technology and electronics resources.) http://www.doctronics.co.uk/meter.htm

Copyright © 2005 by Regents of the University of Colorado

Contributors Sharon D. Perez-Suarez; Jeff Lyng; Malinda Schaefer Zarske; Denise W. Carlson; Janet Yowell

Supporting Program Integrated Teaching and Learning Program, College of Engineering, University of Colorado Boulder

Acknowledgements

The contents of this digital library curriculum were developed under grants from the Fund for the Improvement of Postsecondary Education (FIPSE), U.S. Department of Education, and the National Science Foundation (GK-12 grant no. 0338326). However, these contents do not necessarily represent the policies of the Department of Education or National Science Foundation, and you should not assume endorsement by the federal government.

Last modified: July 9, 2020

# data[].attributes.attachment_link.description
Students use potatoes to light an LED clock (or light bulb) as they learn how a battery works in a simple circuit and how chemical energy changes to electrical energy. As they learn more about electrical energy, they better understand the concepts of voltage, current and resistance.

# data[].attributes.body
We say that energy can be used for food for children, but creating an electrical current to turn on a light bulb is mind blowing for me, let alone a child. To me, this is THE project to get children's minds working. The will begin to think about being resourceful, being creative, how things work, and the unique power of science. -Deborah

# data[].attributes.attachment_link.readable_text
Quick Look

Grade Level: 4 (3-5)

Time Required: 45 minutes

Expendable Cost/Group: US $2.00

Group Size: 3

Activity Dependency: None

Subject Areas: Physical Science, Science and Technology

NGSS Performance Expectations:

Summary Students use potatoes to light an LED clock (or light bulb) as they learn how a battery works in a simple circuit and how chemical energy changes to electrical energy. As they learn more about electrical energy, they better understand the concepts of voltage, current and resistance.
This engineering curriculum aligns to Next Generation Science Standards (NGSS).

Engineering Connection

Engineers use batteries to store energy in a wide range of situations. A solid electrolyte battery is most suitable in very extreme weather conditions, while nickel-zinc batteries work best in electric vehicles. Energy engineers continually evolve technology to improve the performance and life-cycle costs of batteries that store solar and wind energy. When designing a battery, engineers keep in mind the needs of the application, and use different substances to create current flow. They consider characteristics such as power output, ability to recharge, reliability, size, safety, heat generation, length of life cycle, abuse tolerance, cost and ability to be recycled. Isn't the power of engineering creativity amazing?

Learning Objectives

After this activity, students should be able to:

Describe the flow of electrical energy through a simple circuit.

Explain why a light bulb may take more than one battery to light up.

Explain the role of electrical engineers in the development of electricity sources and the products that use electricity.

Educational Standards

Each TeachEngineering lesson or activity is correlated to one or more K-12 science, technology, engineering or math (STEM) educational standards.

All 100,000+ K-12 STEM standards covered in TeachEngineering are collected, maintained and packaged by the Achievement Standards Network (ASN), a project of D2L (www.achievementstandards.org).

In the ASN, standards are hierarchically structured: first by source; e.g., by state; within source by type; e.g., science or mathematics; within type by subtype, then by grade, etc.

NGSS Performance Expectation

Click to view other curriculum aligned to this Performance Expectation

This activity focuses on the following Three Dimensional Learning aspects of NGSS:

Science & Engineering Practices

Disciplinary Core Ideas

Crosscutting Concepts

Make observations to produce data to serve as the basis for evidence for an explanation of a phenomenon or test a design solution.

Energy can be moved from place to place by moving objects or through sound, light, or electric currents. Energy is present whenever there are moving objects, sound, light, or heat. When objects collide, energy can be transferred from one object to another, thereby changing their motion. In such collisions, some energy is typically also transferred to the surrounding air; as a result, the air gets heated and sound is produced. Light also transfers energy from place to place. Energy can also be transferred from place to place by electric currents, which can then be used locally to produce motion, sound, heat, or light. The currents may have been produced to begin with by transforming the energy of motion into electrical energy.

Energy can be transferred in various ways and between objects.

Suggest an alignment not listed above

Materials List

To make a potato battery, each group needs:

3 copper pennies (or copper strips), one per potato

3 zinc nails; these are galvanized nails, available at hardware stores

5 insulated wires, 15-20 cm (6-8 inches) long, with alligator clips at the ends

1 low-current, light emitting diode (LED) clock (or LCD clock) requiring ~1.5 volts (or a small LED)

OR above materials can be purchased cumulatively in a kit, available online

For the entire class to share or one per team:

(optional) multimeter(s) or voltmeter(s); a multimeter measures current, voltage and resistance of a circuit; available at Radio Shack or other electronics stores or websites

Worksheets and Attachments
Visit [www.teachengineering.org/activities/view/cub_energy2_lesson04_activity2] to print or download.

Introduction/Motivation

What is electrical energy? From where does it come? Can you think of anything that needs electrical energy to work? How about lamps, music players, TVs and ovens? How do we get the power to run these devices? What role do electrical engineers play in improving our lives?

One place we can find electrical energy in our homes is at a wall outlet. So, how does electrical energy reach the wall outlet in our house? The energy comes from an electrical power plant, which usually makes electrical energy from burning fossil fuels, such as coal and oil. The heat energy from the burning fuel heats up water. When the water boils, it becomes steam, which flows through a pipe into a turbine (a wheel with blades). As the turbine spins from the steam, it turns a generator (a spinning magnet) that unbalances the charges in nearby atoms and produces a current of electricity. The electrical current flows through protected wires to our house.

How else can we power electrical appliances? That's right, from a battery. A battery works by providing electrons with a solution in which they can move around. Have you ever noticed that some batteries have a copper end that is positive (shown with a plus [+] sign) and another end that is negative (shown with a minus [-] sign)? Zinc is a metal that likes to give its electrons to copper. Usually, zinc just gives its electrons to copper and then the process stops. However, if you provide the electrons with a solution (called an electrolyte) to help them move to the copper, and you give the electrons a wire in which they can move from the copper back to the zinc, you can produce a circuit and a flowing path of electrical energy. (Note: Conventional current flows from positive to negative, so from the copper, through the wire, back to the zinc. The electrons actually flow negative to positive.)

A circuit is a complete path of electrical energy. This means that electrical energy or charge is produced or stored somewhere ( voltage) and has a path for the charge to flow (or current). Another part of a circuit is a resistance, such as a light bulb. Electrical engineers create circuits to help electrical energy perform work, such as lighting a room or keeping food cold. An appliance, light bulb or almost any device that uses electrical energy is a resistance. A resistance prevents or slows an electrical current or charge from moving. When electrical current flows through a source of resistance, it can be changed into light or heat or sound. Even though you cannot see it, the light bulb or appliance slows down the electrical charge.

Electrical engineers help develop the many modern products and appliances that require electrical energy. Electrical engineers also help create the technology used to generate the electrical energy in power plants in the first place. These engineers know a lot about circuits and they continually work to find better ways to store electrical charge and generate electrical current without using nonrenewable fossil fuels such as coal and oil. These electrical engineers are very important in almost everything we do! Essentially, electrical engineers create improvements for society and help save our planet for future generations. Today, we are going to be electrical engineers and learn more about how electrical energy works in a circuit. We are also going to look at generating electrical current from the energy stored in a potato! Do you think we can light a bulb with a potato? Let's try it!

Procedure

Background

How does a potato battery work? The copper (Cu) atoms attract electrons more than the zinc (Zn) atoms. If you place a strip of copper and a strip of zinc in contact with each other, many electrons pass from the zinc to the copper. As they concentrate on the copper, the electrons repel each other. When the force of repulsion between electrons and the force of attraction of electrons to the copper become equalized, the flow of electrons stops. Unfortunately it is not possible to take advantage of this behavior to produce electricity because the flow of charges stops almost immediately. On the other hand, if you bathe the two strips in a conductive solution, and connect them externally with a wire, the reactions between the electrodes and the solution continually furnish the circuit with charges. In this way, the process that produces the electrical energy continues and becomes useful. In a conductive solution, the charge is carried by ions that move through the solution. In the solid state, the ions are not able to move around freely. However, once they are dissolved in water, they become completely mobile. They can "swim" around in the water and thus can respond to an electric current from a battery. That current supplies electrons that cause positive ions to flow in one direction and negative ions to flow in the opposite direction. The ions carry electrical charge from one electrode to another, completing the electrical circuit.

For a conductive solution, use any electrolyte, whether it is an acid, base or salt solution. An electrolyte is a substance whose aqueous solution contains various ions and thus conducts electricity. Therefore, the more free ions a solution has, the better conductor it will be. Many fruits and vegetables contain juices rich in ions and are therefore good electrical conductors.

Like any battery, a potato battery has a limited life span. The electrodes undergo chemical reactions that block the flow of electricity. The electromotive force diminishes and the battery stops working. Usually, what happens is the production of hydrogen at the copper electrode and the zinc electrode acquires deposits of oxides that act as a barrier between the metal and the electrolyte. This is referred to as the electrodes being polarized. To achieve a longer life and higher voltages and current flows, it is necessary to use electrolytes better suited for the purpose. Commercial batteries, apart from their normal electrolyte, contain chemicals with an affinity for hydrogen, which combine with the hydrogen before it can polarize the electrodes.

Before the Activity

With the Students

1. Divide the class into teams of two or three students each. Hand out the materials.

2. Direct groups to carefully place the zinc nails and copper pennies into the potato. Make sure the two different metals do not touch each other in the potato (see Figure 1).

3. Connect one alligator clip to the end of the penny sticking out of the potato and another alligator clip to the end of the nail sticking out of the potato (see Figure 1).

Figure 1. Placement of the nail, penny and alligator clips.

1. (If you have a multimeter) Tell students that a multimeter is an instrument that measures current, voltage and resistance of a circuit, and is a tool (created by and) often used by engineers. Set the multimeter on a low "DC volts" scale for voltage and "DC milliamps" for current, so students can see the charge that one potato can produce. Expect the potato to produce just less than 1 volt. Encourage students to convert the decimal readout from the multimeter to a fraction (for example, 0.82 volts = 82/100 volts).

2. Have the students figure out how many potatoes they need to light their LED clock (or clock). For example, if their potato produces a voltage of 0.8 volts, then they may need two potatoes to power a 1.5 voltage LED.

3. Have students experiment to figure out how to connect two potatoes together. To connect two potatoes in series (to add more voltage), place a penny and nail into a second potato, and connect the wire from the zinc nail in the first potato to the copper penny in the second. Then, add a third wire to the zinc nail in the second potato. Always remember to connect the copper (positive) end of the potato (battery) to the zinc (negative) end of the next potato (see Figure 2).

Figure 2. Activity setup to create a potato battery to power an LED clock.

1. Expect two potatoes in series to be able to light an LED; however, you might need three. Show students how to connect the LEDs to the potato in the correct manner, that is, the positive end of the LED to the negative end of the potato battery (zinc nail) and the negative end of the LED to the positive end of the potato battery (copper penny).

2. Have students discuss how the potatoes provide the electrolyte (solution) for the chemical battery to work. Ask for suggestions of other foods we could try (for example, lemons, berries, apples).

3. Ask students to complete the worksheet either individually or in pairs. After they finish, have them compare answers with a peer or another pair, giving all students time to finish.

Vocabulary/Definitions

conductor: An object that allows the transfer of electrons.

current: The movement of electrons.

electrical energy: Energy produced through the movement of electrons (voltage X current).

electrolyte: A solution that conducts electricity.

energy: The ability to do work.

insulator: An object that inhibits the transfer of electrons.

resistance: Objects or substances that prevent the passage of a steady electric current.

voltage: The amount of energy produced.

Assessment

Pre-Activity Assessment

Brainstorming: In small groups, have students engage in open discussion. Remind them that no idea or suggestion is "silly." All ideas should be respectfully heard. Take an uncritical position, encourage wild ideas and discourage criticism of ideas. Ask students how many items they can think of that run on batteries. As a class, record their ideas on the board.

Quick Poll: Before the activity begins, ask the class a question and tally their responses on the board. Ask: Can we get electrical energy from a fruit or vegetable?

Activity Embedded Assessment

Worksheet /Pairs Check: Have students work individually or in pairs on the Make a Battery Worksheet. After they finish, have them compare answers with a peer or another pair, giving all students time to finish the worksheet.

Hypothesize: Ask each group what would happen if we added more potatoes in a row to our circuits? (Answer: Adding more potatoes in a row is the same as adding batteries in a row. The voltage of each piece of potato is added up. Thus, the voltage of our circuit would increase. On the other hand, the current of our circuit would not increase. Current is not dependent on how many potatoes but is related to the size of each potato individually.)

Post-Activity Assessment

Problem Solving: Present the class with the following math problems and ask students to calculate how many of each vegetable or fruit are needed to light the bulb.

If a lemon produces 1 Volt of energy, how many lemons would you need to light a 2 Volt light bulb? (Answer: 2)

If a potato produces 0.8 Volts of energy, how many potatoes would you need to light a 1.5 Volt light bulb? (Answer: 2)

If a potato produces 0.8 Volts of energy, how many potatoes would you need to light a 3 Volt digital clock? (Answer: 4)

If you have a lemon that produces 1 Volt of energy and an apple that produces 1 Volt of energy, can you light a 3 Volt clock? (Answer: No, you would need one more lemon or apple.)

Diagramming: Engineers must understand how circuits work in order to develop cool new technologies. Draw a picture of your potato battery. Label the battery (voltage) and the resistance (light bulb). Draw an arrow to show the current flow (from the copper end to the zinc end). List two cool products that an engineer could develop that run off a fruit battery.

Troubleshooting Tips

If the LED clock, light or small light bulbs do not work, check the setup of the potato battery. Perhaps the ends are not all connected from negative to positive, or perhaps there is not enough potato voltage. Check the voltage of the potato using a multimeter or voltmeter. Another possibility is having enough voltage, but not enough current to light the bulb, which is why it is recommended to use only very low-volt LED clocks or bulbs. Also, try using more potatoes (i.e., 5 potato halves) to strengthen conductivity. Try different LED colors (for example, the blue LED may work better than the red).

Lemons and oranges also work well for this activity. They work best if you first roll them on a table top, which breaks down the cells inside so more juice flows through the fruit (current).

Some people have more conduction success using copper strips instead of copper pennies (can also wrap the pennies in copper ribbon).

Soaking the potatoes in Gatorade overnight can make them more conductive.

Activity Extensions

At activity end, before students disassemble their potato batteries, it is fun to have the entire class connect their fruit batteries in series, making "a serious tater circle."

Have students try the activity again using different fruits or vegetables! Many fruits and vegetables work, such as lemons, limes, apples and carrots. Have students compare and contrast the performance of different fruits and vegetables.

Have students complete the activity again using an electrolyte solution, such as salt water or vinegar. Have them compare and contrast the performance of different electrolyte solutions.

To add a math component, have students use the multimeter to compare the flow of electricity for several different fruits as well as to the total amount of fruits used. Ask them to graph the results and hypothesize what is happening.

Activity Scaling

Have more advanced students experiment with parallel and series configurations using different numbers of potatoes.

References

Dictionary.com. Lexico Publishing Group, LLC. Accessed September 28, 2005. (Source of some vocabulary definitions, with some adaptation) http://www.dictionary.com

Phillips, W.D. Chapter 2P: Using a Multimeter. Design Electronics (online textbook) DOCTRONICS Educational Publishing, UK. Accessed September 28, 2005. (Good design, technology and electronics resources.) http://www.doctronics.co.uk/meter.htm

Copyright © 2005 by Regents of the University of Colorado

Contributors Sharon D. Perez-Suarez; Jeff Lyng; Malinda Schaefer Zarske; Denise W. Carlson; Janet Yowell

Supporting Program Integrated Teaching and Learning Program, College of Engineering, University of Colorado Boulder

Acknowledgements

The contents of this digital library curriculum were developed under grants from the Fund for the Improvement of Postsecondary Education (FIPSE), U.S. Department of Education, and the National Science Foundation (GK-12 grant no. 0338326). However, these contents do not necessarily represent the policies of the Department of Education or National Science Foundation, and you should not assume endorsement by the federal government.

Last modified: July 9, 2020

# data[].attributes.attachment_link.description
Students use potatoes to light an LED clock (or light bulb) as they learn how a battery works in a simple circuit and how chemical energy changes to electrical energy. As they learn more about electrical energy, they better understand the concepts of voltage, current and resistance.

# data[].attributes.body
I chose this lesson because it seemed interesting to me personally. It also seems like a lesson that will make the students critically think. This lesson also includes many different standards so it is hitting many different aspects, and it includes many 21st Century Skills.

# data[].attributes.attachment_link.readable_text
Quick Look

Grade Level: 4 (3-5)

Time Required: 45 minutes

Expendable Cost/Group: US $2.00

Group Size: 3

Activity Dependency: None

Subject Areas: Physical Science, Science and Technology

NGSS Performance Expectations:

Summary Students use potatoes to light an LED clock (or light bulb) as they learn how a battery works in a simple circuit and how chemical energy changes to electrical energy. As they learn more about electrical energy, they better understand the concepts of voltage, current and resistance.
This engineering curriculum aligns to Next Generation Science Standards (NGSS).

Engineering Connection

Engineers use batteries to store energy in a wide range of situations. A solid electrolyte battery is most suitable in very extreme weather conditions, while nickel-zinc batteries work best in electric vehicles. Energy engineers continually evolve technology to improve the performance and life-cycle costs of batteries that store solar and wind energy. When designing a battery, engineers keep in mind the needs of the application, and use different substances to create current flow. They consider characteristics such as power output, ability to recharge, reliability, size, safety, heat generation, length of life cycle, abuse tolerance, cost and ability to be recycled. Isn't the power of engineering creativity amazing?

Learning Objectives

After this activity, students should be able to:

Describe the flow of electrical energy through a simple circuit.

Explain why a light bulb may take more than one battery to light up.

Explain the role of electrical engineers in the development of electricity sources and the products that use electricity.

Educational Standards

Each TeachEngineering lesson or activity is correlated to one or more K-12 science, technology, engineering or math (STEM) educational standards.

All 100,000+ K-12 STEM standards covered in TeachEngineering are collected, maintained and packaged by the Achievement Standards Network (ASN), a project of D2L (www.achievementstandards.org).

In the ASN, standards are hierarchically structured: first by source; e.g., by state; within source by type; e.g., science or mathematics; within type by subtype, then by grade, etc.

NGSS Performance Expectation

Click to view other curriculum aligned to this Performance Expectation

This activity focuses on the following Three Dimensional Learning aspects of NGSS:

Science & Engineering Practices

Disciplinary Core Ideas

Crosscutting Concepts

Make observations to produce data to serve as the basis for evidence for an explanation of a phenomenon or test a design solution.

Energy can be moved from place to place by moving objects or through sound, light, or electric currents. Energy is present whenever there are moving objects, sound, light, or heat. When objects collide, energy can be transferred from one object to another, thereby changing their motion. In such collisions, some energy is typically also transferred to the surrounding air; as a result, the air gets heated and sound is produced. Light also transfers energy from place to place. Energy can also be transferred from place to place by electric currents, which can then be used locally to produce motion, sound, heat, or light. The currents may have been produced to begin with by transforming the energy of motion into electrical energy.

Energy can be transferred in various ways and between objects.

Suggest an alignment not listed above

Materials List

To make a potato battery, each group needs:

3 copper pennies (or copper strips), one per potato

3 zinc nails; these are galvanized nails, available at hardware stores

5 insulated wires, 15-20 cm (6-8 inches) long, with alligator clips at the ends

1 low-current, light emitting diode (LED) clock (or LCD clock) requiring ~1.5 volts (or a small LED)

OR above materials can be purchased cumulatively in a kit, available online

For the entire class to share or one per team:

(optional) multimeter(s) or voltmeter(s); a multimeter measures current, voltage and resistance of a circuit; available at Radio Shack or other electronics stores or websites

Worksheets and Attachments
Visit [www.teachengineering.org/activities/view/cub_energy2_lesson04_activity2] to print or download.

Introduction/Motivation

What is electrical energy? From where does it come? Can you think of anything that needs electrical energy to work? How about lamps, music players, TVs and ovens? How do we get the power to run these devices? What role do electrical engineers play in improving our lives?

One place we can find electrical energy in our homes is at a wall outlet. So, how does electrical energy reach the wall outlet in our house? The energy comes from an electrical power plant, which usually makes electrical energy from burning fossil fuels, such as coal and oil. The heat energy from the burning fuel heats up water. When the water boils, it becomes steam, which flows through a pipe into a turbine (a wheel with blades). As the turbine spins from the steam, it turns a generator (a spinning magnet) that unbalances the charges in nearby atoms and produces a current of electricity. The electrical current flows through protected wires to our house.

How else can we power electrical appliances? That's right, from a battery. A battery works by providing electrons with a solution in which they can move around. Have you ever noticed that some batteries have a copper end that is positive (shown with a plus [+] sign) and another end that is negative (shown with a minus [-] sign)? Zinc is a metal that likes to give its electrons to copper. Usually, zinc just gives its electrons to copper and then the process stops. However, if you provide the electrons with a solution (called an electrolyte) to help them move to the copper, and you give the electrons a wire in which they can move from the copper back to the zinc, you can produce a circuit and a flowing path of electrical energy. (Note: Conventional current flows from positive to negative, so from the copper, through the wire, back to the zinc. The electrons actually flow negative to positive.)

A circuit is a complete path of electrical energy. This means that electrical energy or charge is produced or stored somewhere ( voltage) and has a path for the charge to flow (or current). Another part of a circuit is a resistance, such as a light bulb. Electrical engineers create circuits to help electrical energy perform work, such as lighting a room or keeping food cold. An appliance, light bulb or almost any device that uses electrical energy is a resistance. A resistance prevents or slows an electrical current or charge from moving. When electrical current flows through a source of resistance, it can be changed into light or heat or sound. Even though you cannot see it, the light bulb or appliance slows down the electrical charge.

Electrical engineers help develop the many modern products and appliances that require electrical energy. Electrical engineers also help create the technology used to generate the electrical energy in power plants in the first place. These engineers know a lot about circuits and they continually work to find better ways to store electrical charge and generate electrical current without using nonrenewable fossil fuels such as coal and oil. These electrical engineers are very important in almost everything we do! Essentially, electrical engineers create improvements for society and help save our planet for future generations. Today, we are going to be electrical engineers and learn more about how electrical energy works in a circuit. We are also going to look at generating electrical current from the energy stored in a potato! Do you think we can light a bulb with a potato? Let's try it!

Procedure

Background

How does a potato battery work? The copper (Cu) atoms attract electrons more than the zinc (Zn) atoms. If you place a strip of copper and a strip of zinc in contact with each other, many electrons pass from the zinc to the copper. As they concentrate on the copper, the electrons repel each other. When the force of repulsion between electrons and the force of attraction of electrons to the copper become equalized, the flow of electrons stops. Unfortunately it is not possible to take advantage of this behavior to produce electricity because the flow of charges stops almost immediately. On the other hand, if you bathe the two strips in a conductive solution, and connect them externally with a wire, the reactions between the electrodes and the solution continually furnish the circuit with charges. In this way, the process that produces the electrical energy continues and becomes useful. In a conductive solution, the charge is carried by ions that move through the solution. In the solid state, the ions are not able to move around freely. However, once they are dissolved in water, they become completely mobile. They can "swim" around in the water and thus can respond to an electric current from a battery. That current supplies electrons that cause positive ions to flow in one direction and negative ions to flow in the opposite direction. The ions carry electrical charge from one electrode to another, completing the electrical circuit.

For a conductive solution, use any electrolyte, whether it is an acid, base or salt solution. An electrolyte is a substance whose aqueous solution contains various ions and thus conducts electricity. Therefore, the more free ions a solution has, the better conductor it will be. Many fruits and vegetables contain juices rich in ions and are therefore good electrical conductors.

Like any battery, a potato battery has a limited life span. The electrodes undergo chemical reactions that block the flow of electricity. The electromotive force diminishes and the battery stops working. Usually, what happens is the production of hydrogen at the copper electrode and the zinc electrode acquires deposits of oxides that act as a barrier between the metal and the electrolyte. This is referred to as the electrodes being polarized. To achieve a longer life and higher voltages and current flows, it is necessary to use electrolytes better suited for the purpose. Commercial batteries, apart from their normal electrolyte, contain chemicals with an affinity for hydrogen, which combine with the hydrogen before it can polarize the electrodes.

Before the Activity

With the Students

1. Divide the class into teams of two or three students each. Hand out the materials.

2. Direct groups to carefully place the zinc nails and copper pennies into the potato. Make sure the two different metals do not touch each other in the potato (see Figure 1).

3. Connect one alligator clip to the end of the penny sticking out of the potato and another alligator clip to the end of the nail sticking out of the potato (see Figure 1).

Figure 1. Placement of the nail, penny and alligator clips.

1. (If you have a multimeter) Tell students that a multimeter is an instrument that measures current, voltage and resistance of a circuit, and is a tool (created by and) often used by engineers. Set the multimeter on a low "DC volts" scale for voltage and "DC milliamps" for current, so students can see the charge that one potato can produce. Expect the potato to produce just less than 1 volt. Encourage students to convert the decimal readout from the multimeter to a fraction (for example, 0.82 volts = 82/100 volts).

2. Have the students figure out how many potatoes they need to light their LED clock (or clock). For example, if their potato produces a voltage of 0.8 volts, then they may need two potatoes to power a 1.5 voltage LED.

3. Have students experiment to figure out how to connect two potatoes together. To connect two potatoes in series (to add more voltage), place a penny and nail into a second potato, and connect the wire from the zinc nail in the first potato to the copper penny in the second. Then, add a third wire to the zinc nail in the second potato. Always remember to connect the copper (positive) end of the potato (battery) to the zinc (negative) end of the next potato (see Figure 2).

Figure 2. Activity setup to create a potato battery to power an LED clock.

1. Expect two potatoes in series to be able to light an LED; however, you might need three. Show students how to connect the LEDs to the potato in the correct manner, that is, the positive end of the LED to the negative end of the potato battery (zinc nail) and the negative end of the LED to the positive end of the potato battery (copper penny).

2. Have students discuss how the potatoes provide the electrolyte (solution) for the chemical battery to work. Ask for suggestions of other foods we could try (for example, lemons, berries, apples).

3. Ask students to complete the worksheet either individually or in pairs. After they finish, have them compare answers with a peer or another pair, giving all students time to finish.

Vocabulary/Definitions

conductor: An object that allows the transfer of electrons.

current: The movement of electrons.

electrical energy: Energy produced through the movement of electrons (voltage X current).

electrolyte: A solution that conducts electricity.

energy: The ability to do work.

insulator: An object that inhibits the transfer of electrons.

resistance: Objects or substances that prevent the passage of a steady electric current.

voltage: The amount of energy produced.

Assessment

Pre-Activity Assessment

Brainstorming: In small groups, have students engage in open discussion. Remind them that no idea or suggestion is "silly." All ideas should be respectfully heard. Take an uncritical position, encourage wild ideas and discourage criticism of ideas. Ask students how many items they can think of that run on batteries. As a class, record their ideas on the board.

Quick Poll: Before the activity begins, ask the class a question and tally their responses on the board. Ask: Can we get electrical energy from a fruit or vegetable?

Activity Embedded Assessment

Worksheet /Pairs Check: Have students work individually or in pairs on the Make a Battery Worksheet. After they finish, have them compare answers with a peer or another pair, giving all students time to finish the worksheet.

Hypothesize: Ask each group what would happen if we added more potatoes in a row to our circuits? (Answer: Adding more potatoes in a row is the same as adding batteries in a row. The voltage of each piece of potato is added up. Thus, the voltage of our circuit would increase. On the other hand, the current of our circuit would not increase. Current is not dependent on how many potatoes but is related to the size of each potato individually.)

Post-Activity Assessment

Problem Solving: Present the class with the following math problems and ask students to calculate how many of each vegetable or fruit are needed to light the bulb.

If a lemon produces 1 Volt of energy, how many lemons would you need to light a 2 Volt light bulb? (Answer: 2)

If a potato produces 0.8 Volts of energy, how many potatoes would you need to light a 1.5 Volt light bulb? (Answer: 2)

If a potato produces 0.8 Volts of energy, how many potatoes would you need to light a 3 Volt digital clock? (Answer: 4)

If you have a lemon that produces 1 Volt of energy and an apple that produces 1 Volt of energy, can you light a 3 Volt clock? (Answer: No, you would need one more lemon or apple.)

Diagramming: Engineers must understand how circuits work in order to develop cool new technologies. Draw a picture of your potato battery. Label the battery (voltage) and the resistance (light bulb). Draw an arrow to show the current flow (from the copper end to the zinc end). List two cool products that an engineer could develop that run off a fruit battery.

Troubleshooting Tips

If the LED clock, light or small light bulbs do not work, check the setup of the potato battery. Perhaps the ends are not all connected from negative to positive, or perhaps there is not enough potato voltage. Check the voltage of the potato using a multimeter or voltmeter. Another possibility is having enough voltage, but not enough current to light the bulb, which is why it is recommended to use only very low-volt LED clocks or bulbs. Also, try using more potatoes (i.e., 5 potato halves) to strengthen conductivity. Try different LED colors (for example, the blue LED may work better than the red).

Lemons and oranges also work well for this activity. They work best if you first roll them on a table top, which breaks down the cells inside so more juice flows through the fruit (current).

Some people have more conduction success using copper strips instead of copper pennies (can also wrap the pennies in copper ribbon).

Soaking the potatoes in Gatorade overnight can make them more conductive.

Activity Extensions

At activity end, before students disassemble their potato batteries, it is fun to have the entire class connect their fruit batteries in series, making "a serious tater circle."

Have students try the activity again using different fruits or vegetables! Many fruits and vegetables work, such as lemons, limes, apples and carrots. Have students compare and contrast the performance of different fruits and vegetables.

Have students complete the activity again using an electrolyte solution, such as salt water or vinegar. Have them compare and contrast the performance of different electrolyte solutions.

To add a math component, have students use the multimeter to compare the flow of electricity for several different fruits as well as to the total amount of fruits used. Ask them to graph the results and hypothesize what is happening.

Activity Scaling

Have more advanced students experiment with parallel and series configurations using different numbers of potatoes.

References

Dictionary.com. Lexico Publishing Group, LLC. Accessed September 28, 2005. (Source of some vocabulary definitions, with some adaptation) http://www.dictionary.com

Phillips, W.D. Chapter 2P: Using a Multimeter. Design Electronics (online textbook) DOCTRONICS Educational Publishing, UK. Accessed September 28, 2005. (Good design, technology and electronics resources.) http://www.doctronics.co.uk/meter.htm

Copyright © 2005 by Regents of the University of Colorado

Contributors Sharon D. Perez-Suarez; Jeff Lyng; Malinda Schaefer Zarske; Denise W. Carlson; Janet Yowell

Supporting Program Integrated Teaching and Learning Program, College of Engineering, University of Colorado Boulder

Acknowledgements

The contents of this digital library curriculum were developed under grants from the Fund for the Improvement of Postsecondary Education (FIPSE), U.S. Department of Education, and the National Science Foundation (GK-12 grant no. 0338326). However, these contents do not necessarily represent the policies of the Department of Education or National Science Foundation, and you should not assume endorsement by the federal government.

Last modified: July 9, 2020

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Students use potatoes to light an LED clock (or light bulb) as they learn how a battery works in a simple circuit and how chemical energy changes to electrical energy. As they learn more about electrical energy, they better understand the concepts of voltage, current and resistance.

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I picked this lesson because it has cheap/simple materials to get and it’s fun. There are numerous ISTE Standards involved with this lesson as well as 21st Century Skills.

- Kaylee Garman

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Posted on by ASEE

(Lesson Courtesy COSI Columbus - The Center for Science and Industry). Level: Grades 4 - 8. Time required: 30 to 50 minutes. Click HERE for PDF of activity. Click HERE for version developed by Ohio State University engineering graduate students and Maize Elementary teachers

Overview

This simple catapult activity for students in grades 4 - 8 teaches them how energy is transferred when a plastic spoon is pulled back, then released, rocketing its payload - a single marshmallow.

Background

What's going on? The plastic spoon has an inherent elasticity, which means it will return to its original shape after being deformed. Rubber bands and other elastic objects also have this property. When the spoon is deformed, the force used to cause that deformation is "stored" in the spoon as elastic potential energy. When the spoon is released, the elastic potential energy changes to kinetic energy as the spoon returns to its original shape, carrying the marshmallow along with it. The marshmallow continues to move after the spoon has stopped due to its inertia.

Catapult Information

(from the Museum of Ancient Inventions, Smith College)

The catapult was an ancient siege machine that could hurl heavy objects or shoot arrows with great force and for considerable distances. Some catapults could throw stones weighing as much as 350 pounds for distances greater than 300 feet.

The Greek Dionysius the Elder of Syracuse, who was looking to develop a new type of weapon, invented the catapult about 400 BCE. Thereafter, it became a key weapon in warfare and remained so up through mediaeval times. Two major catapults evolved from Dionysius's invention: the double-armed machine, or ballista, used for shooting arrows, and the single-armed catapult designed for hurling large objects. Although the Romans added wheels to both types of catapult for maneuverability, very little in the design of the machine changed.The reconstruction shown here is of a single-armed stone-hurling catapult, approximately two feet long and one-and-a-half feet tall. Its hurling arm is driven by a cocked, winch-pulled cord.

Standards (Ohio)

Physical Science: 1.6, 3.3, 3.4, 7.2, 7.4

Vocabulary

elasticity, potential energy, kinetic energy, deflection angle

Materials

Plastic spoon

1-2 bags of miniature marshmallows

marking pens

tape measure or meter stick

masking tape

protractor

safety goggles

Procedure
Instruction for teachers:
Set up the classroom so that you have at least 20 feet of open space in front of the launching area for a landing area. Have students put on goggles, then align teams of 3-4 students along one side of a set of long tables or a counter so the catapults will be aimed across the room.

Distribute to each group safety goggles, spoons, marshmallows, protractors, and lengths of masking tape.
Instructions for students:
1. Prepare your catapult by taping a spoon firmly against the edge of a table, perpendicular to the tabletop with the bowl of the spoon facing toward the table.

2. Mark your marshmallows for identification with a pen, using your group initials.

3. Test the setup of your catapult and marshmallow: Hold the marshmallow in the bowl of the spoon. Use your thumb to help anchor the spoon handle against the table.

4. Practice launch: Keeping the end of the spoon handle against the table, launching the marshmallow across the room. (Don't point it at anyone!)

5. Experiment with pulling the spoon back farther to change the angle - what are the results?

Now, determine the best deflection angle - how far you pull back the spoon - to launch the marshmallow the farthest possible distance. Decide how much to deflect the spoon, using a protractor to measure the angle between the spoon and the table. Record the measurements of your deflection angle on a sheet of paper, then launch your marshmallow and measure the distance it travels. Repeat this two more times and compute the average of the three.

6. Now, change the deflection angle of the catapult and repeat. Record the average distance for three separate different catapult angles. Record your results. What angle between the spoon and table launches the marshmallow the farthest?

7. Based on your data, predict the optimum deflection angle.

8. Hold a class contest to find out who can make a marshmallow fly the farthest.

Extensions

Ask the class what would happen if they changed the weight/size of the marshmallow - and how could they do that? Which other techniques could makes the marshmallow go farther? Higher?

Spoons may be made of several different types of plastic. Bring in other plastic spoons and try this experiment. Compare and contrast the results. Look up the properties of the different types of plastic and relate these properties to the results.

For homework, challenge students to come up with their own catapult design - still using the marshmallow load - then allow them to construct, test, and demonstrate their models in class the next day. What innovative solutions did each group devise? Have students evaluate their results and those of their classmates.

Assign students to research the history of catapults. When were they used, and for what purposes?

Resources

More ancient inventions at Smith College's online Museum of Ancient Inventions
http://www.middle-ages.org.uk/catapults.htm http://www.medieval-castle-siege-weapons.com/medieval-catapults.html
Filed under: Class Activities, Grades 6-8, Grades K-5, Grades K-5, Lesson Plans

Tags: catapult, Class Activities, forces and motion, Fun & Games, Grades 4 - 8, Grades K-5, Newton's Laws, Physical Science, Physics, trebuchet

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eGFI - For Teachers " Activity: Catapult Marshmallow Launch

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Posted on by ASEE (Lesson Courtesy COSI Columbus - The Center for Science and Industry). Level: Grades 4 - 8. Time required: 30 to 50 minutes. Click HERE for PDF of activity.

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Sara Kashatus
I really liked this lesson because of all the materials it gives you and the information it has for you to properly do the lesson. I think using a potato to explore and teach about energy is really cool because it shows students how you can integrate technology without using a computer or iPad. Also, this kind of lesson gives students a huge sense of pride and accomplishment when they see how it works.

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Quick Look

Grade Level: 4 (3-5)

Time Required: 45 minutes

Expendable Cost/Group: US $2.00

Group Size: 3

Activity Dependency: None

Subject Areas: Physical Science, Science and Technology

NGSS Performance Expectations:

Summary Students use potatoes to light an LED clock (or light bulb) as they learn how a battery works in a simple circuit and how chemical energy changes to electrical energy. As they learn more about electrical energy, they better understand the concepts of voltage, current and resistance.
This engineering curriculum aligns to Next Generation Science Standards (NGSS).

Engineering Connection

Engineers use batteries to store energy in a wide range of situations. A solid electrolyte battery is most suitable in very extreme weather conditions, while nickel-zinc batteries work best in electric vehicles. Energy engineers continually evolve technology to improve the performance and life-cycle costs of batteries that store solar and wind energy. When designing a battery, engineers keep in mind the needs of the application, and use different substances to create current flow. They consider characteristics such as power output, ability to recharge, reliability, size, safety, heat generation, length of life cycle, abuse tolerance, cost and ability to be recycled. Isn't the power of engineering creativity amazing?

Learning Objectives

After this activity, students should be able to:

Describe the flow of electrical energy through a simple circuit.

Explain why a light bulb may take more than one battery to light up.

Explain the role of electrical engineers in the development of electricity sources and the products that use electricity.

Educational Standards

Each TeachEngineering lesson or activity is correlated to one or more K-12 science, technology, engineering or math (STEM) educational standards.

All 100,000+ K-12 STEM standards covered in TeachEngineering are collected, maintained and packaged by the Achievement Standards Network (ASN), a project of D2L (www.achievementstandards.org).

In the ASN, standards are hierarchically structured: first by source; e.g., by state; within source by type; e.g., science or mathematics; within type by subtype, then by grade, etc.

NGSS Performance Expectation

Click to view other curriculum aligned to this Performance Expectation

This activity focuses on the following Three Dimensional Learning aspects of NGSS:

Science & Engineering Practices

Disciplinary Core Ideas

Crosscutting Concepts

Make observations to produce data to serve as the basis for evidence for an explanation of a phenomenon or test a design solution.

Energy can be moved from place to place by moving objects or through sound, light, or electric currents. Energy is present whenever there are moving objects, sound, light, or heat. When objects collide, energy can be transferred from one object to another, thereby changing their motion. In such collisions, some energy is typically also transferred to the surrounding air; as a result, the air gets heated and sound is produced. Light also transfers energy from place to place. Energy can also be transferred from place to place by electric currents, which can then be used locally to produce motion, sound, heat, or light. The currents may have been produced to begin with by transforming the energy of motion into electrical energy.

Energy can be transferred in various ways and between objects.

Suggest an alignment not listed above

Materials List

To make a potato battery, each group needs:

3 copper pennies (or copper strips), one per potato

3 zinc nails; these are galvanized nails, available at hardware stores

5 insulated wires, 15-20 cm (6-8 inches) long, with alligator clips at the ends

1 low-current, light emitting diode (LED) clock (or LCD clock) requiring ~1.5 volts (or a small LED)

OR above materials can be purchased cumulatively in a kit, available online

For the entire class to share or one per team:

(optional) multimeter(s) or voltmeter(s); a multimeter measures current, voltage and resistance of a circuit; available at Radio Shack or other electronics stores or websites

Worksheets and Attachments
Visit [www.teachengineering.org/activities/view/cub_energy2_lesson04_activity2] to print or download.

Introduction/Motivation

What is electrical energy? From where does it come? Can you think of anything that needs electrical energy to work? How about lamps, music players, TVs and ovens? How do we get the power to run these devices? What role do electrical engineers play in improving our lives?

One place we can find electrical energy in our homes is at a wall outlet. So, how does electrical energy reach the wall outlet in our house? The energy comes from an electrical power plant, which usually makes electrical energy from burning fossil fuels, such as coal and oil. The heat energy from the burning fuel heats up water. When the water boils, it becomes steam, which flows through a pipe into a turbine (a wheel with blades). As the turbine spins from the steam, it turns a generator (a spinning magnet) that unbalances the charges in nearby atoms and produces a current of electricity. The electrical current flows through protected wires to our house.

How else can we power electrical appliances? That's right, from a battery. A battery works by providing electrons with a solution in which they can move around. Have you ever noticed that some batteries have a copper end that is positive (shown with a plus [+] sign) and another end that is negative (shown with a minus [-] sign)? Zinc is a metal that likes to give its electrons to copper. Usually, zinc just gives its electrons to copper and then the process stops. However, if you provide the electrons with a solution (called an electrolyte) to help them move to the copper, and you give the electrons a wire in which they can move from the copper back to the zinc, you can produce a circuit and a flowing path of electrical energy. (Note: Conventional current flows from positive to negative, so from the copper, through the wire, back to the zinc. The electrons actually flow negative to positive.)

A circuit is a complete path of electrical energy. This means that electrical energy or charge is produced or stored somewhere ( voltage) and has a path for the charge to flow (or current). Another part of a circuit is a resistance, such as a light bulb. Electrical engineers create circuits to help electrical energy perform work, such as lighting a room or keeping food cold. An appliance, light bulb or almost any device that uses electrical energy is a resistance. A resistance prevents or slows an electrical current or charge from moving. When electrical current flows through a source of resistance, it can be changed into light or heat or sound. Even though you cannot see it, the light bulb or appliance slows down the electrical charge.

Electrical engineers help develop the many modern products and appliances that require electrical energy. Electrical engineers also help create the technology used to generate the electrical energy in power plants in the first place. These engineers know a lot about circuits and they continually work to find better ways to store electrical charge and generate electrical current without using nonrenewable fossil fuels such as coal and oil. These electrical engineers are very important in almost everything we do! Essentially, electrical engineers create improvements for society and help save our planet for future generations. Today, we are going to be electrical engineers and learn more about how electrical energy works in a circuit. We are also going to look at generating electrical current from the energy stored in a potato! Do you think we can light a bulb with a potato? Let's try it!

Procedure

Background

How does a potato battery work? The copper (Cu) atoms attract electrons more than the zinc (Zn) atoms. If you place a strip of copper and a strip of zinc in contact with each other, many electrons pass from the zinc to the copper. As they concentrate on the copper, the electrons repel each other. When the force of repulsion between electrons and the force of attraction of electrons to the copper become equalized, the flow of electrons stops. Unfortunately it is not possible to take advantage of this behavior to produce electricity because the flow of charges stops almost immediately. On the other hand, if you bathe the two strips in a conductive solution, and connect them externally with a wire, the reactions between the electrodes and the solution continually furnish the circuit with charges. In this way, the process that produces the electrical energy continues and becomes useful. In a conductive solution, the charge is carried by ions that move through the solution. In the solid state, the ions are not able to move around freely. However, once they are dissolved in water, they become completely mobile. They can "swim" around in the water and thus can respond to an electric current from a battery. That current supplies electrons that cause positive ions to flow in one direction and negative ions to flow in the opposite direction. The ions carry electrical charge from one electrode to another, completing the electrical circuit.

For a conductive solution, use any electrolyte, whether it is an acid, base or salt solution. An electrolyte is a substance whose aqueous solution contains various ions and thus conducts electricity. Therefore, the more free ions a solution has, the better conductor it will be. Many fruits and vegetables contain juices rich in ions and are therefore good electrical conductors.

Like any battery, a potato battery has a limited life span. The electrodes undergo chemical reactions that block the flow of electricity. The electromotive force diminishes and the battery stops working. Usually, what happens is the production of hydrogen at the copper electrode and the zinc electrode acquires deposits of oxides that act as a barrier between the metal and the electrolyte. This is referred to as the electrodes being polarized. To achieve a longer life and higher voltages and current flows, it is necessary to use electrolytes better suited for the purpose. Commercial batteries, apart from their normal electrolyte, contain chemicals with an affinity for hydrogen, which combine with the hydrogen before it can polarize the electrodes.

Before the Activity

With the Students

1. Divide the class into teams of two or three students each. Hand out the materials.

2. Direct groups to carefully place the zinc nails and copper pennies into the potato. Make sure the two different metals do not touch each other in the potato (see Figure 1).

3. Connect one alligator clip to the end of the penny sticking out of the potato and another alligator clip to the end of the nail sticking out of the potato (see Figure 1).

Figure 1. Placement of the nail, penny and alligator clips.

1. (If you have a multimeter) Tell students that a multimeter is an instrument that measures current, voltage and resistance of a circuit, and is a tool (created by and) often used by engineers. Set the multimeter on a low "DC volts" scale for voltage and "DC milliamps" for current, so students can see the charge that one potato can produce. Expect the potato to produce just less than 1 volt. Encourage students to convert the decimal readout from the multimeter to a fraction (for example, 0.82 volts = 82/100 volts).

2. Have the students figure out how many potatoes they need to light their LED clock (or clock). For example, if their potato produces a voltage of 0.8 volts, then they may need two potatoes to power a 1.5 voltage LED.

3. Have students experiment to figure out how to connect two potatoes together. To connect two potatoes in series (to add more voltage), place a penny and nail into a second potato, and connect the wire from the zinc nail in the first potato to the copper penny in the second. Then, add a third wire to the zinc nail in the second potato. Always remember to connect the copper (positive) end of the potato (battery) to the zinc (negative) end of the next potato (see Figure 2).

Figure 2. Activity setup to create a potato battery to power an LED clock.

1. Expect two potatoes in series to be able to light an LED; however, you might need three. Show students how to connect the LEDs to the potato in the correct manner, that is, the positive end of the LED to the negative end of the potato battery (zinc nail) and the negative end of the LED to the positive end of the potato battery (copper penny).

2. Have students discuss how the potatoes provide the electrolyte (solution) for the chemical battery to work. Ask for suggestions of other foods we could try (for example, lemons, berries, apples).

3. Ask students to complete the worksheet either individually or in pairs. After they finish, have them compare answers with a peer or another pair, giving all students time to finish.

Vocabulary/Definitions

conductor: An object that allows the transfer of electrons.

current: The movement of electrons.

electrical energy: Energy produced through the movement of electrons (voltage X current).

electrolyte: A solution that conducts electricity.

energy: The ability to do work.

insulator: An object that inhibits the transfer of electrons.

resistance: Objects or substances that prevent the passage of a steady electric current.

voltage: The amount of energy produced.

Assessment

Pre-Activity Assessment

Brainstorming: In small groups, have students engage in open discussion. Remind them that no idea or suggestion is "silly." All ideas should be respectfully heard. Take an uncritical position, encourage wild ideas and discourage criticism of ideas. Ask students how many items they can think of that run on batteries. As a class, record their ideas on the board.

Quick Poll: Before the activity begins, ask the class a question and tally their responses on the board. Ask: Can we get electrical energy from a fruit or vegetable?

Activity Embedded Assessment

Worksheet /Pairs Check: Have students work individually or in pairs on the Make a Battery Worksheet. After they finish, have them compare answers with a peer or another pair, giving all students time to finish the worksheet.

Hypothesize: Ask each group what would happen if we added more potatoes in a row to our circuits? (Answer: Adding more potatoes in a row is the same as adding batteries in a row. The voltage of each piece of potato is added up. Thus, the voltage of our circuit would increase. On the other hand, the current of our circuit would not increase. Current is not dependent on how many potatoes but is related to the size of each potato individually.)

Post-Activity Assessment

Problem Solving: Present the class with the following math problems and ask students to calculate how many of each vegetable or fruit are needed to light the bulb.

If a lemon produces 1 Volt of energy, how many lemons would you need to light a 2 Volt light bulb? (Answer: 2)

If a potato produces 0.8 Volts of energy, how many potatoes would you need to light a 1.5 Volt light bulb? (Answer: 2)

If a potato produces 0.8 Volts of energy, how many potatoes would you need to light a 3 Volt digital clock? (Answer: 4)

If you have a lemon that produces 1 Volt of energy and an apple that produces 1 Volt of energy, can you light a 3 Volt clock? (Answer: No, you would need one more lemon or apple.)

Diagramming: Engineers must understand how circuits work in order to develop cool new technologies. Draw a picture of your potato battery. Label the battery (voltage) and the resistance (light bulb). Draw an arrow to show the current flow (from the copper end to the zinc end). List two cool products that an engineer could develop that run off a fruit battery.

Troubleshooting Tips

If the LED clock, light or small light bulbs do not work, check the setup of the potato battery. Perhaps the ends are not all connected from negative to positive, or perhaps there is not enough potato voltage. Check the voltage of the potato using a multimeter or voltmeter. Another possibility is having enough voltage, but not enough current to light the bulb, which is why it is recommended to use only very low-volt LED clocks or bulbs. Also, try using more potatoes (i.e., 5 potato halves) to strengthen conductivity. Try different LED colors (for example, the blue LED may work better than the red).

Lemons and oranges also work well for this activity. They work best if you first roll them on a table top, which breaks down the cells inside so more juice flows through the fruit (current).

Some people have more conduction success using copper strips instead of copper pennies (can also wrap the pennies in copper ribbon).

Soaking the potatoes in Gatorade overnight can make them more conductive.

Activity Extensions

At activity end, before students disassemble their potato batteries, it is fun to have the entire class connect their fruit batteries in series, making "a serious tater circle."

Have students try the activity again using different fruits or vegetables! Many fruits and vegetables work, such as lemons, limes, apples and carrots. Have students compare and contrast the performance of different fruits and vegetables.

Have students complete the activity again using an electrolyte solution, such as salt water or vinegar. Have them compare and contrast the performance of different electrolyte solutions.

To add a math component, have students use the multimeter to compare the flow of electricity for several different fruits as well as to the total amount of fruits used. Ask them to graph the results and hypothesize what is happening.

Activity Scaling

Have more advanced students experiment with parallel and series configurations using different numbers of potatoes.

References

Dictionary.com. Lexico Publishing Group, LLC. Accessed September 28, 2005. (Source of some vocabulary definitions, with some adaptation) http://www.dictionary.com

Phillips, W.D. Chapter 2P: Using a Multimeter. Design Electronics (online textbook) DOCTRONICS Educational Publishing, UK. Accessed September 28, 2005. (Good design, technology and electronics resources.) http://www.doctronics.co.uk/meter.htm

Copyright © 2005 by Regents of the University of Colorado

Contributors Sharon D. Perez-Suarez; Jeff Lyng; Malinda Schaefer Zarske; Denise W. Carlson; Janet Yowell

Supporting Program Integrated Teaching and Learning Program, College of Engineering, University of Colorado Boulder

Acknowledgements

The contents of this digital library curriculum were developed under grants from the Fund for the Improvement of Postsecondary Education (FIPSE), U.S. Department of Education, and the National Science Foundation (GK-12 grant no. 0338326). However, these contents do not necessarily represent the policies of the Department of Education or National Science Foundation, and you should not assume endorsement by the federal government.

Last modified: July 9, 2020

# data[].attributes.attachment_link.description
Students use potatoes to light an LED clock (or light bulb) as they learn how a battery works in a simple circuit and how chemical energy changes to electrical energy. As they learn more about electrical energy, they better understand the concepts of voltage, current and resistance.

# data[].attributes.body
I liked this lesson because it included multiple parts of STEM rather than just the one and covered a lot of 21st century skills. The worksheet included covered a lot and I think the students would enjoy going to the aquarium and documenting what they observe.
-Avery

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I chose this lesson because even though it doesn't include technology, it still is interactive and STEAM based for students. It is simple, and doesn't require many materials but it is something that will likely keep the students interested. I also did something like this in elementary school and really enjoyed it.

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Posted on by ASEE

(Lesson Courtesy COSI Columbus - The Center for Science and Industry). Level: Grades 4 - 8. Time required: 30 to 50 minutes. Click HERE for PDF of activity. Click HERE for version developed by Ohio State University engineering graduate students and Maize Elementary teachers

Overview

This simple catapult activity for students in grades 4 - 8 teaches them how energy is transferred when a plastic spoon is pulled back, then released, rocketing its payload - a single marshmallow.

Background

What's going on? The plastic spoon has an inherent elasticity, which means it will return to its original shape after being deformed. Rubber bands and other elastic objects also have this property. When the spoon is deformed, the force used to cause that deformation is "stored" in the spoon as elastic potential energy. When the spoon is released, the elastic potential energy changes to kinetic energy as the spoon returns to its original shape, carrying the marshmallow along with it. The marshmallow continues to move after the spoon has stopped due to its inertia.

Catapult Information

(from the Museum of Ancient Inventions, Smith College)

The catapult was an ancient siege machine that could hurl heavy objects or shoot arrows with great force and for considerable distances. Some catapults could throw stones weighing as much as 350 pounds for distances greater than 300 feet.

The Greek Dionysius the Elder of Syracuse, who was looking to develop a new type of weapon, invented the catapult about 400 BCE. Thereafter, it became a key weapon in warfare and remained so up through mediaeval times. Two major catapults evolved from Dionysius's invention: the double-armed machine, or ballista, used for shooting arrows, and the single-armed catapult designed for hurling large objects. Although the Romans added wheels to both types of catapult for maneuverability, very little in the design of the machine changed.The reconstruction shown here is of a single-armed stone-hurling catapult, approximately two feet long and one-and-a-half feet tall. Its hurling arm is driven by a cocked, winch-pulled cord.

Standards (Ohio)

Physical Science: 1.6, 3.3, 3.4, 7.2, 7.4

Vocabulary

elasticity, potential energy, kinetic energy, deflection angle

Materials

Plastic spoon

1-2 bags of miniature marshmallows

marking pens

tape measure or meter stick

masking tape

protractor

safety goggles

Procedure
Instruction for teachers:
Set up the classroom so that you have at least 20 feet of open space in front of the launching area for a landing area. Have students put on goggles, then align teams of 3-4 students along one side of a set of long tables or a counter so the catapults will be aimed across the room.

Distribute to each group safety goggles, spoons, marshmallows, protractors, and lengths of masking tape.
Instructions for students:
1. Prepare your catapult by taping a spoon firmly against the edge of a table, perpendicular to the tabletop with the bowl of the spoon facing toward the table.

2. Mark your marshmallows for identification with a pen, using your group initials.

3. Test the setup of your catapult and marshmallow: Hold the marshmallow in the bowl of the spoon. Use your thumb to help anchor the spoon handle against the table.

4. Practice launch: Keeping the end of the spoon handle against the table, launching the marshmallow across the room. (Don't point it at anyone!)

5. Experiment with pulling the spoon back farther to change the angle - what are the results?

Now, determine the best deflection angle - how far you pull back the spoon - to launch the marshmallow the farthest possible distance. Decide how much to deflect the spoon, using a protractor to measure the angle between the spoon and the table. Record the measurements of your deflection angle on a sheet of paper, then launch your marshmallow and measure the distance it travels. Repeat this two more times and compute the average of the three.

6. Now, change the deflection angle of the catapult and repeat. Record the average distance for three separate different catapult angles. Record your results. What angle between the spoon and table launches the marshmallow the farthest?

7. Based on your data, predict the optimum deflection angle.

8. Hold a class contest to find out who can make a marshmallow fly the farthest.

Extensions

Ask the class what would happen if they changed the weight/size of the marshmallow - and how could they do that? Which other techniques could makes the marshmallow go farther? Higher?

Spoons may be made of several different types of plastic. Bring in other plastic spoons and try this experiment. Compare and contrast the results. Look up the properties of the different types of plastic and relate these properties to the results.

For homework, challenge students to come up with their own catapult design - still using the marshmallow load - then allow them to construct, test, and demonstrate their models in class the next day. What innovative solutions did each group devise? Have students evaluate their results and those of their classmates.

Assign students to research the history of catapults. When were they used, and for what purposes?

Resources

More ancient inventions at Smith College's online Museum of Ancient Inventions
http://www.middle-ages.org.uk/catapults.htm http://www.medieval-castle-siege-weapons.com/medieval-catapults.html
Filed under: Class Activities, Grades 6-8, Grades K-5, Grades K-5, Lesson Plans

Tags: catapult, Class Activities, forces and motion, Fun & Games, Grades 4 - 8, Grades K-5, Newton's Laws, Physical Science, Physics, trebuchet

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eGFI - For Teachers " Activity: Catapult Marshmallow Launch

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Posted on by ASEE (Lesson Courtesy COSI Columbus - The Center for Science and Industry). Level: Grades 4 - 8. Time required: 30 to 50 minutes. Click HERE for PDF of activity.

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This lesson had me at marshmallows, but also made me laugh because of the safety goggles. For children, it's fun doing an experiment that is "dangerous" because they will be using a catapult effect with sweet small pillow like objects. Children can use their imagination, but also learn the power of inertia and kinetic energy. -Deborah

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Posted on by ASEE

(Lesson Courtesy COSI Columbus - The Center for Science and Industry). Level: Grades 4 - 8. Time required: 30 to 50 minutes. Click HERE for PDF of activity. Click HERE for version developed by Ohio State University engineering graduate students and Maize Elementary teachers

Overview

This simple catapult activity for students in grades 4 - 8 teaches them how energy is transferred when a plastic spoon is pulled back, then released, rocketing its payload - a single marshmallow.

Background

What's going on? The plastic spoon has an inherent elasticity, which means it will return to its original shape after being deformed. Rubber bands and other elastic objects also have this property. When the spoon is deformed, the force used to cause that deformation is "stored" in the spoon as elastic potential energy. When the spoon is released, the elastic potential energy changes to kinetic energy as the spoon returns to its original shape, carrying the marshmallow along with it. The marshmallow continues to move after the spoon has stopped due to its inertia.

Catapult Information

(from the Museum of Ancient Inventions, Smith College)

The catapult was an ancient siege machine that could hurl heavy objects or shoot arrows with great force and for considerable distances. Some catapults could throw stones weighing as much as 350 pounds for distances greater than 300 feet.

The Greek Dionysius the Elder of Syracuse, who was looking to develop a new type of weapon, invented the catapult about 400 BCE. Thereafter, it became a key weapon in warfare and remained so up through mediaeval times. Two major catapults evolved from Dionysius's invention: the double-armed machine, or ballista, used for shooting arrows, and the single-armed catapult designed for hurling large objects. Although the Romans added wheels to both types of catapult for maneuverability, very little in the design of the machine changed.The reconstruction shown here is of a single-armed stone-hurling catapult, approximately two feet long and one-and-a-half feet tall. Its hurling arm is driven by a cocked, winch-pulled cord.

Standards (Ohio)

Physical Science: 1.6, 3.3, 3.4, 7.2, 7.4

Vocabulary

elasticity, potential energy, kinetic energy, deflection angle

Materials

Plastic spoon

1-2 bags of miniature marshmallows

marking pens

tape measure or meter stick

masking tape

protractor

safety goggles

Procedure
Instruction for teachers:
Set up the classroom so that you have at least 20 feet of open space in front of the launching area for a landing area. Have students put on goggles, then align teams of 3-4 students along one side of a set of long tables or a counter so the catapults will be aimed across the room.

Distribute to each group safety goggles, spoons, marshmallows, protractors, and lengths of masking tape.
Instructions for students:
1. Prepare your catapult by taping a spoon firmly against the edge of a table, perpendicular to the tabletop with the bowl of the spoon facing toward the table.

2. Mark your marshmallows for identification with a pen, using your group initials.

3. Test the setup of your catapult and marshmallow: Hold the marshmallow in the bowl of the spoon. Use your thumb to help anchor the spoon handle against the table.

4. Practice launch: Keeping the end of the spoon handle against the table, launching the marshmallow across the room. (Don't point it at anyone!)

5. Experiment with pulling the spoon back farther to change the angle - what are the results?

Now, determine the best deflection angle - how far you pull back the spoon - to launch the marshmallow the farthest possible distance. Decide how much to deflect the spoon, using a protractor to measure the angle between the spoon and the table. Record the measurements of your deflection angle on a sheet of paper, then launch your marshmallow and measure the distance it travels. Repeat this two more times and compute the average of the three.

6. Now, change the deflection angle of the catapult and repeat. Record the average distance for three separate different catapult angles. Record your results. What angle between the spoon and table launches the marshmallow the farthest?

7. Based on your data, predict the optimum deflection angle.

8. Hold a class contest to find out who can make a marshmallow fly the farthest.

Extensions

Ask the class what would happen if they changed the weight/size of the marshmallow - and how could they do that? Which other techniques could makes the marshmallow go farther? Higher?

Spoons may be made of several different types of plastic. Bring in other plastic spoons and try this experiment. Compare and contrast the results. Look up the properties of the different types of plastic and relate these properties to the results.

For homework, challenge students to come up with their own catapult design - still using the marshmallow load - then allow them to construct, test, and demonstrate their models in class the next day. What innovative solutions did each group devise? Have students evaluate their results and those of their classmates.

Assign students to research the history of catapults. When were they used, and for what purposes?

Resources

More ancient inventions at Smith College's online Museum of Ancient Inventions
http://www.middle-ages.org.uk/catapults.htm http://www.medieval-castle-siege-weapons.com/medieval-catapults.html
Filed under: Class Activities, Grades 6-8, Grades K-5, Grades K-5, Lesson Plans

Tags: catapult, Class Activities, forces and motion, Fun & Games, Grades 4 - 8, Grades K-5, Newton's Laws, Physical Science, Physics, trebuchet

# data[].attributes.attachment_link.title
eGFI - For Teachers " Activity: Catapult Marshmallow Launch

# data[].attributes.attachment_link.description
Posted on by ASEE (Lesson Courtesy COSI Columbus - The Center for Science and Industry). Level: Grades 4 - 8. Time required: 30 to 50 minutes. Click HERE for PDF of activity.

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I chose this lesson because it is great practice for young students and it allows them to be active. They get to walk around to try to find different shapes.
-Taylor Sciubba

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I have learned that kids absolutely love a scavenger hunt. It can be anything really. From completely random to a set of clues. It can be as easy or as complicated as you'd like. Most people think of outdoor, or nature, scavenger hunts, but they can be for learning, and inside too!

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I chose this lesson because I like how it isn't a once and done activity. This is something that will be continued and talked about for days. It also shows students how easily everyday objects can be turned into something else. The ISTE standards and 21st Century Skills are also beneficial.

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Make plastic from milk? It seems like some sort of lactose intolerant horror story, but it's actually a really cool science process. Create your own toys, beads, jewelry, and more, with ingredients you have right now in your kitchen. It's so easy and super cool!

Turn Milk Into Plastic Toys!
Disclaimer: This article may contain commission or affiliate links. As an Amazon Associate I earn from qualifying purchases.
Not seeing our videos? Turn off any adblockers to ensure our video feed can be seen.
Also known as casein plastic, this process has been used for over 100 years and is the way they used to make plastics before 1945 when synthetic plastics were introduced. Even royalty wore jewelry made from milk plastic many years ago. How cool is that?

With this simple process you can make toys, beads, jewelry, decorative pieces and more. This is a great, budget friendly experiment, with spectacular results that will have your students pumped with excitement for science!

A stove top or microwave to warm the milk
Milk (we used 2%, lower fat content is better)
White Vinegar or Lemon Juice
Bowl
Spoon
Strainer (or can create your own using cheese cloth or similar)
Paper towel
Molds (we loved using our Lego minifigures and Dinosaur molds) or other tools for shaping.

Time: 30 to 90 minutes for the experiment, then 2 days for drying. Add in a little extra time for painting once dry!

Measure out 1 cup of milk (you can also use chocolate milk and the end result smells amazing!), this makes about 4 minifigures or 4 dinosaurs. Heat on the stove top in a pot or in the microwave in a heat resistant bowl. You want it to just start steaming. Remove from the heat. Add 4 tsp of vinegar or lemon juice and stir gently.

The amount of vinegar is not exact. We used 4 tbsp by accident and it was fine, just made for a more intense vinegar smell!

You will notice that it immediately begins to curdle. You're making curds and whey!

Stir gently for approximately one minute for the full reaction to finish and all the curds to form. Don't stir aggressively. Be gentle.

Strain off the whey using a strainer or you can use cheese cloth (or similar). Let drip for a few minutes until most of the liquid has drained off. Gently smoosh the curds around in the strainer if needed.

Now remove the curds and place them on a few layers of paper towel. Carefully pat and squish to remove more liquid. You may need to replace the paper towel and repeat a few times. The goal is to remove as much liquid as possible.

You will notice it is kind of crumbly and squishy, but you can smoosh and shape it.

Now you can put it in your molds at this point but we discovered that if you put the curds in a jar or bowl, soaking in vinegar for an hour, you will get a much smoother final product. Plus they are more white if you do this extra step. If you do the extra vinegar soak, once the hour is up, repeat the straining, and paper towel drying process again. This time you will notice it is smoother in texture and no longer crumbly.

During the vinegar soak you can add some food colouring if you want. Just put a few drops in with the vinegar while it is soaking and it will colour the curds. Or make yours glow in the dark with our favourite trick!

Now squish it into your molds. We used silicone molds to make Lego minifigs and dinosaurs.

You can also shape it by hand. Roll it to create beads, then use a skewer to put a hole through it before setting it aside to dry. Or flatten it and use some cookie cutters.

The drying process takes time, approximately 2 days depending on your natural humidity levels and how much moisture you removed with the paper towels. But you can remove it from the silicone molds after 24 hours and this will help speed up the drying time.

Once dry, clean up the edges a bit if necessary, just like you would with any other casting. You can do this with just your fingers, a piece of sand paper or other tools. It will be hard plastic now, so it might take a little extra work!

You can paint the final products with either acrylic paints or markers. I used acrylic paints and a sharpie for the faces on mine. Spray them with a clear coat to give them a nice shine once you are finished.

VOILA! Who knew it was so easy, and so much fun, to make plastic from milk!

Our oldest Milk Plastic Toys are over 2 years old now and show no signs of degrading. We haven't done any experiments yet to see if they might break down with moisture, or heat, or sun, but that might go on the books for a future study. They are definitely highly durable!

This is a chemistry experiment working with polymers. Polymers are molecules that have formed a regular chain structure. Milk contains molecules of a protein called Casein. During this reaction between warm milk and acid the casein molecules unfold and form long chains called a polymer. The polymer can be molded and shaped which makes it a plastic. In this case it's called casein plastic or milk plastic because of the type of molecules that created the plastic.

More STEM activities

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Make Milk Plastic in the Kitchen Chemistry Project for Kids

# data[].attributes.attachment_link.description
Make plastic from milk? It seems like some sort of lactose intolerant horror story, but it's actually a really cool science process. Create your own toys, beads, jewelry, and more, with ingredients you have right now in your kitchen. It's so easy and super cool! Disclaimer: This article may contain commission or affiliate links.

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Sara Kashatus
I love the Monterey Bay Aquarium and I think that this is an awesome lesson. I really like how flexible it is and how you could use this for more than one grade level. If you as a teacher are not able to get to an aquarium to do this lesson the Monterey Bay Aquarium has live webcams that you could show to the class. A digital story book is a great way to include technology in a lesson about real world animals.

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The best feeling a teacher gets, (one of) is getting children excited to learn. Telling children they can make a toy from a material that they drink from a daily basis, or even using the analogy of a cow making toys would create a ripple of laughter. Children who never considered themselves artists would start creating sketches or ideas of their toy. Unique, for sure. -Deborah

# data[].attributes.attachment_link.readable_text
Make plastic from milk? It seems like some sort of lactose intolerant horror story, but it's actually a really cool science process. Create your own toys, beads, jewelry, and more, with ingredients you have right now in your kitchen. It's so easy and super cool!

Turn Milk Into Plastic Toys!
Disclaimer: This article may contain commission or affiliate links. As an Amazon Associate I earn from qualifying purchases.
Not seeing our videos? Turn off any adblockers to ensure our video feed can be seen.
Also known as casein plastic, this process has been used for over 100 years and is the way they used to make plastics before 1945 when synthetic plastics were introduced. Even royalty wore jewelry made from milk plastic many years ago. How cool is that?

With this simple process you can make toys, beads, jewelry, decorative pieces and more. This is a great, budget friendly experiment, with spectacular results that will have your students pumped with excitement for science!

A stove top or microwave to warm the milk
Milk (we used 2%, lower fat content is better)
White Vinegar or Lemon Juice
Bowl
Spoon
Strainer (or can create your own using cheese cloth or similar)
Paper towel
Molds (we loved using our Lego minifigures and Dinosaur molds) or other tools for shaping.

Time: 30 to 90 minutes for the experiment, then 2 days for drying. Add in a little extra time for painting once dry!

Measure out 1 cup of milk (you can also use chocolate milk and the end result smells amazing!), this makes about 4 minifigures or 4 dinosaurs. Heat on the stove top in a pot or in the microwave in a heat resistant bowl. You want it to just start steaming. Remove from the heat. Add 4 tsp of vinegar or lemon juice and stir gently.

The amount of vinegar is not exact. We used 4 tbsp by accident and it was fine, just made for a more intense vinegar smell!

You will notice that it immediately begins to curdle. You're making curds and whey!

Stir gently for approximately one minute for the full reaction to finish and all the curds to form. Don't stir aggressively. Be gentle.

Strain off the whey using a strainer or you can use cheese cloth (or similar). Let drip for a few minutes until most of the liquid has drained off. Gently smoosh the curds around in the strainer if needed.

Now remove the curds and place them on a few layers of paper towel. Carefully pat and squish to remove more liquid. You may need to replace the paper towel and repeat a few times. The goal is to remove as much liquid as possible.

You will notice it is kind of crumbly and squishy, but you can smoosh and shape it.

Now you can put it in your molds at this point but we discovered that if you put the curds in a jar or bowl, soaking in vinegar for an hour, you will get a much smoother final product. Plus they are more white if you do this extra step. If you do the extra vinegar soak, once the hour is up, repeat the straining, and paper towel drying process again. This time you will notice it is smoother in texture and no longer crumbly.

During the vinegar soak you can add some food colouring if you want. Just put a few drops in with the vinegar while it is soaking and it will colour the curds. Or make yours glow in the dark with our favourite trick!

Now squish it into your molds. We used silicone molds to make Lego minifigs and dinosaurs.

You can also shape it by hand. Roll it to create beads, then use a skewer to put a hole through it before setting it aside to dry. Or flatten it and use some cookie cutters.

The drying process takes time, approximately 2 days depending on your natural humidity levels and how much moisture you removed with the paper towels. But you can remove it from the silicone molds after 24 hours and this will help speed up the drying time.

Once dry, clean up the edges a bit if necessary, just like you would with any other casting. You can do this with just your fingers, a piece of sand paper or other tools. It will be hard plastic now, so it might take a little extra work!

You can paint the final products with either acrylic paints or markers. I used acrylic paints and a sharpie for the faces on mine. Spray them with a clear coat to give them a nice shine once you are finished.

VOILA! Who knew it was so easy, and so much fun, to make plastic from milk!

Our oldest Milk Plastic Toys are over 2 years old now and show no signs of degrading. We haven't done any experiments yet to see if they might break down with moisture, or heat, or sun, but that might go on the books for a future study. They are definitely highly durable!

This is a chemistry experiment working with polymers. Polymers are molecules that have formed a regular chain structure. Milk contains molecules of a protein called Casein. During this reaction between warm milk and acid the casein molecules unfold and form long chains called a polymer. The polymer can be molded and shaped which makes it a plastic. In this case it's called casein plastic or milk plastic because of the type of molecules that created the plastic.

More STEM activities

# data[].attributes.attachment_link.title
Make Milk Plastic in the Kitchen Chemistry Project for Kids

# data[].attributes.attachment_link.description
Make plastic from milk? It seems like some sort of lactose intolerant horror story, but it's actually a really cool science process. Create your own toys, beads, jewelry, and more, with ingredients you have right now in your kitchen. It's so easy and super cool! Disclaimer: This article may contain commission or affiliate links.

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I would chose the Oobleck lesson because out of the two it’s the easiest to accomplish in the classroom. It’s also fun for the students to create and see how the substance can change due to the pressure that’s being added to it.

- Kaylee Garman

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Have you ever read Dr. Seuss? I'm pretty sure everyone with kids has! Did you know that Dr. Seuss created the name of one of our favourite science experiments? Yup, Oobleck got it's name from Bartholomew and the Oobleck, a story about a bored king with a team of magicians at his disposal. You can imagine the chaos! So we created our own Bartholomew and the Oobleck inspired STEM activity to recreate the story. It was marvelously messy hands on STEM learning!

Bartholomew and the Oobleck - Dr. Seuss Inspired Learning
Disclaimer: This post contains affiliate links
Oobleck - non-Newtonian Fluid

We love a great science experiment, especially when it is a rule breaker like Oobleck. Known as a non-Newtonian fluid, oobleck breaks Newton's Laws of Fluid Dynamics. To understand this law think about how liquids normally behave. Water flows smoothly and freely, but mix in a bit of dirt to create mud and it slows down. This is because the dynamics (behaviours) of fluids are affected by their viscosity and density.

Want to learn more about the science of oobleck? Check out this article on our Colour Changing Oobleck or our Glow in the Dark Oobleck Activity for lots of great scientific details.

Dr. Seuss' Bartholomew and the Oobleck

As much as we love oobleck, we had never read the book that inspired the name. So I set out to get the book and add it to our collection. It turns out this was a little harder than I anticipated. See the book was published in 1949 (and won the Caldecott Honor-winning picture book 1950). Since this book is quite old, it wasn't available in any of my local bookstores. In the end I ordered it online. It was definitely worth it (even though I do prefer to visit bookstores in person!).

The book is about a bored king, King Derwin of Didd. Why is he so bored? He is bored by the weather. Sun, rain, fog and snow are just much too boring for him. So he tasks his team of royal magicians to create a new weather to make him happy.

The result is this sticky, gloppy creation that rains from the skies and creates complete havoc for the entire village.

In the end the king learns a valuable lesson about the power of words and we are introduced to the wonders of oobleck!

After reading the book we decided it would make amazing inspiration for a STEM activity.

Bartholomew and the Oobleck STEM Activity Supplies

To do this STEM activity you will need items you likely already have laying around the house.

Bartholomew and the Oobleck - it makes sense to have the book so you can do this as a full unit study!
Cornstarch
Water
Green food colouring
Bowl
Spoon
Lego - plates, blocks and minifigs
Some type of mesh (you could even build a grid from Lego pieces if you prefer)
Large, shallow edged dish
Easy to clean space

Bartholomew and the Oobleck Inspired STEM Project

After reading the book together, we were ready for our oobleck STEM activity.

First up we needed to build our "village". We built two walls with 2x bricks on a baseplate. Then we attached our mesh to the top. The weight of the oobleck did cause our walls to tip in. So we supported the walls with a few extra bricks at the bottom. Next time I would encourage the kids to come up with other ways to make the walls sturdier, such as adding beams or a grid to the top. This worked, but it wasn't the most stable construction with the weight of the oobleck added to the top.

Next we added our villagers! Don't they look like happy little villagers just going about their day? Except of course the oobleck raining down on their heads!

Once it was all built we carefully placed it all in a large shallow lipped tray to catch all the mess. Then we placed it on a table in an easy to clean up area. Oobleck is messy fun, so always plan ahead for easy clean up.

Now it was time to mix up our oobleck! Oobleck is soooo easy to make. Simply take 2 cups of cornstarch and 1 cup of water and add to a large bowl. Since the oobleck was green in Bartholomew and the Oobleck, we coloured our water green first before mixing it with the cornstarch.

Almost immediately you will start to see that non-Newtonian fluid dynamic as you try and mix it all together. The trick is to move slowly. The more pressure you place on the oobleck the harder it will get.

Once mixed it was time to reenact the book!

Oobleck, King Derwin and the Village of Didd

Before we started my son insisted on adding a minifig to represent King Derwin. He chose a knight and placed it at the very top, where he could see the chaos he unleashed on the people.

Now it was time for the magicians to unleash their magic goop - Oobleck!

We carefully scooped up the oobleck and added it to the top of our mesh. We watched as it would clump, then run, then clump and run. It was clump as it hit the mesh, then liquify and run through the mesh, but then it would clump again as it hit other bits of oobleck falling down. As it hit our village and our innocent villagers it would once again clump. It was fascinating to watch!

Now if your children have never used oobleck, you should spend some time letting them explore the properties of oobleck with their hands. It is such a cool substance that turns solid under pressure and liquefies when you remove the pressure. Having an understanding of those properties before starting this experiment will help them understand why it behaves in such a strange way as it rains down on their village.

The gloopy oobleck made for some really funny moments. Oobleck hat anyone?

CHECK OUT THE OOBLECK IN ACTION AS IT RAINS DOWN ON OUR VILLAGE!

MORE GREAT OOBLECK STUDIES

Oobleck is a fantastic science study. Check out some of our other oobleck projects.
Colour Changing Oobleck (acid-base study) Halloween Oobleck Game Glow in the Dark Oobleck Introduction to Oobleck
Have fun exploring this non-Newtonian fluid rule breaker in your science lessons!

MORE LEGO STEM ACTIVITIES

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Bartholomew and the Oobleck STEM Activity for elementary

# data[].attributes.attachment_link.description
Have you ever read Dr. Seuss? I'm pretty sure everyone with kids has! Did you know that Dr. Seuss created the name of one of our favourite science experiments? Yup, Oobleck got it's name from Bartholomew and the Oobleck , a story about a bored king with a team of magicians at his disposal.

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I really like that this lesson also includes a reading which I think is good that they are implementing multiple content areas along with STEM. I also think that students would just enjoy learning about different states of matter through making messy slime.
-Avery

# data[].attributes.attachment_link.readable_text
Have you ever read Dr. Seuss? I'm pretty sure everyone with kids has! Did you know that Dr. Seuss created the name of one of our favourite science experiments? Yup, Oobleck got it's name from Bartholomew and the Oobleck, a story about a bored king with a team of magicians at his disposal. You can imagine the chaos! So we created our own Bartholomew and the Oobleck inspired STEM activity to recreate the story. It was marvelously messy hands on STEM learning!

Bartholomew and the Oobleck - Dr. Seuss Inspired Learning
Disclaimer: This post contains affiliate links
Oobleck - non-Newtonian Fluid

We love a great science experiment, especially when it is a rule breaker like Oobleck. Known as a non-Newtonian fluid, oobleck breaks Newton's Laws of Fluid Dynamics. To understand this law think about how liquids normally behave. Water flows smoothly and freely, but mix in a bit of dirt to create mud and it slows down. This is because the dynamics (behaviours) of fluids are affected by their viscosity and density.

Want to learn more about the science of oobleck? Check out this article on our Colour Changing Oobleck or our Glow in the Dark Oobleck Activity for lots of great scientific details.

Dr. Seuss' Bartholomew and the Oobleck

As much as we love oobleck, we had never read the book that inspired the name. So I set out to get the book and add it to our collection. It turns out this was a little harder than I anticipated. See the book was published in 1949 (and won the Caldecott Honor-winning picture book 1950). Since this book is quite old, it wasn't available in any of my local bookstores. In the end I ordered it online. It was definitely worth it (even though I do prefer to visit bookstores in person!).

The book is about a bored king, King Derwin of Didd. Why is he so bored? He is bored by the weather. Sun, rain, fog and snow are just much too boring for him. So he tasks his team of royal magicians to create a new weather to make him happy.

The result is this sticky, gloppy creation that rains from the skies and creates complete havoc for the entire village.

In the end the king learns a valuable lesson about the power of words and we are introduced to the wonders of oobleck!

After reading the book we decided it would make amazing inspiration for a STEM activity.

Bartholomew and the Oobleck STEM Activity Supplies

To do this STEM activity you will need items you likely already have laying around the house.

Bartholomew and the Oobleck - it makes sense to have the book so you can do this as a full unit study!
Cornstarch
Water
Green food colouring
Bowl
Spoon
Lego - plates, blocks and minifigs
Some type of mesh (you could even build a grid from Lego pieces if you prefer)
Large, shallow edged dish
Easy to clean space

Bartholomew and the Oobleck Inspired STEM Project

After reading the book together, we were ready for our oobleck STEM activity.

First up we needed to build our "village". We built two walls with 2x bricks on a baseplate. Then we attached our mesh to the top. The weight of the oobleck did cause our walls to tip in. So we supported the walls with a few extra bricks at the bottom. Next time I would encourage the kids to come up with other ways to make the walls sturdier, such as adding beams or a grid to the top. This worked, but it wasn't the most stable construction with the weight of the oobleck added to the top.

Next we added our villagers! Don't they look like happy little villagers just going about their day? Except of course the oobleck raining down on their heads!

Once it was all built we carefully placed it all in a large shallow lipped tray to catch all the mess. Then we placed it on a table in an easy to clean up area. Oobleck is messy fun, so always plan ahead for easy clean up.

Now it was time to mix up our oobleck! Oobleck is soooo easy to make. Simply take 2 cups of cornstarch and 1 cup of water and add to a large bowl. Since the oobleck was green in Bartholomew and the Oobleck, we coloured our water green first before mixing it with the cornstarch.

Almost immediately you will start to see that non-Newtonian fluid dynamic as you try and mix it all together. The trick is to move slowly. The more pressure you place on the oobleck the harder it will get.

Once mixed it was time to reenact the book!

Oobleck, King Derwin and the Village of Didd

Before we started my son insisted on adding a minifig to represent King Derwin. He chose a knight and placed it at the very top, where he could see the chaos he unleashed on the people.

Now it was time for the magicians to unleash their magic goop - Oobleck!

We carefully scooped up the oobleck and added it to the top of our mesh. We watched as it would clump, then run, then clump and run. It was clump as it hit the mesh, then liquify and run through the mesh, but then it would clump again as it hit other bits of oobleck falling down. As it hit our village and our innocent villagers it would once again clump. It was fascinating to watch!

Now if your children have never used oobleck, you should spend some time letting them explore the properties of oobleck with their hands. It is such a cool substance that turns solid under pressure and liquefies when you remove the pressure. Having an understanding of those properties before starting this experiment will help them understand why it behaves in such a strange way as it rains down on their village.

The gloopy oobleck made for some really funny moments. Oobleck hat anyone?

CHECK OUT THE OOBLECK IN ACTION AS IT RAINS DOWN ON OUR VILLAGE!

MORE GREAT OOBLECK STUDIES

Oobleck is a fantastic science study. Check out some of our other oobleck projects.
Colour Changing Oobleck (acid-base study) Halloween Oobleck Game Glow in the Dark Oobleck Introduction to Oobleck
Have fun exploring this non-Newtonian fluid rule breaker in your science lessons!

MORE LEGO STEM ACTIVITIES

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Bartholomew and the Oobleck STEM Activity for elementary

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Have you ever read Dr. Seuss? I'm pretty sure everyone with kids has! Did you know that Dr. Seuss created the name of one of our favourite science experiments? Yup, Oobleck got it's name from Bartholomew and the Oobleck , a story about a bored king with a team of magicians at his disposal.

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I chose this lesson because I found it to be the most interesting. It also seemed to be more experiment-focused than the other lesson, which I liked. I think students would also enjoy it so it might keep them engaged. They may also use critical thinking skills.
-Taylor Sciubba

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Quick Look

Grade Level: 4 (3-5)

Time Required: 45 minutes

Expendable Cost/Group: US $2.00

Group Size: 3

Activity Dependency: None

Subject Areas: Physical Science, Science and Technology

NGSS Performance Expectations:

Summary Students use potatoes to light an LED clock (or light bulb) as they learn how a battery works in a simple circuit and how chemical energy changes to electrical energy. As they learn more about electrical energy, they better understand the concepts of voltage, current and resistance.
This engineering curriculum aligns to Next Generation Science Standards (NGSS).

Engineering Connection

Engineers use batteries to store energy in a wide range of situations. A solid electrolyte battery is most suitable in very extreme weather conditions, while nickel-zinc batteries work best in electric vehicles. Energy engineers continually evolve technology to improve the performance and life-cycle costs of batteries that store solar and wind energy. When designing a battery, engineers keep in mind the needs of the application, and use different substances to create current flow. They consider characteristics such as power output, ability to recharge, reliability, size, safety, heat generation, length of life cycle, abuse tolerance, cost and ability to be recycled. Isn't the power of engineering creativity amazing?

Learning Objectives

After this activity, students should be able to:

Describe the flow of electrical energy through a simple circuit.

Explain why a light bulb may take more than one battery to light up.

Explain the role of electrical engineers in the development of electricity sources and the products that use electricity.

Educational Standards

Each TeachEngineering lesson or activity is correlated to one or more K-12 science, technology, engineering or math (STEM) educational standards.

All 100,000+ K-12 STEM standards covered in TeachEngineering are collected, maintained and packaged by the Achievement Standards Network (ASN), a project of D2L (www.achievementstandards.org).

In the ASN, standards are hierarchically structured: first by source; e.g., by state; within source by type; e.g., science or mathematics; within type by subtype, then by grade, etc.

NGSS Performance Expectation

Click to view other curriculum aligned to this Performance Expectation

This activity focuses on the following Three Dimensional Learning aspects of NGSS:

Science & Engineering Practices

Disciplinary Core Ideas

Crosscutting Concepts

Make observations to produce data to serve as the basis for evidence for an explanation of a phenomenon or test a design solution.

Energy can be moved from place to place by moving objects or through sound, light, or electric currents. Energy is present whenever there are moving objects, sound, light, or heat. When objects collide, energy can be transferred from one object to another, thereby changing their motion. In such collisions, some energy is typically also transferred to the surrounding air; as a result, the air gets heated and sound is produced. Light also transfers energy from place to place. Energy can also be transferred from place to place by electric currents, which can then be used locally to produce motion, sound, heat, or light. The currents may have been produced to begin with by transforming the energy of motion into electrical energy.

Energy can be transferred in various ways and between objects.

Suggest an alignment not listed above

Materials List

To make a potato battery, each group needs:

3 copper pennies (or copper strips), one per potato

3 zinc nails; these are galvanized nails, available at hardware stores

5 insulated wires, 15-20 cm (6-8 inches) long, with alligator clips at the ends

1 low-current, light emitting diode (LED) clock (or LCD clock) requiring ~1.5 volts (or a small LED)

OR above materials can be purchased cumulatively in a kit, available online

For the entire class to share or one per team:

(optional) multimeter(s) or voltmeter(s); a multimeter measures current, voltage and resistance of a circuit; available at Radio Shack or other electronics stores or websites

Worksheets and Attachments
Visit [www.teachengineering.org/activities/view/cub_energy2_lesson04_activity2] to print or download.

Introduction/Motivation

What is electrical energy? From where does it come? Can you think of anything that needs electrical energy to work? How about lamps, music players, TVs and ovens? How do we get the power to run these devices? What role do electrical engineers play in improving our lives?

One place we can find electrical energy in our homes is at a wall outlet. So, how does electrical energy reach the wall outlet in our house? The energy comes from an electrical power plant, which usually makes electrical energy from burning fossil fuels, such as coal and oil. The heat energy from the burning fuel heats up water. When the water boils, it becomes steam, which flows through a pipe into a turbine (a wheel with blades). As the turbine spins from the steam, it turns a generator (a spinning magnet) that unbalances the charges in nearby atoms and produces a current of electricity. The electrical current flows through protected wires to our house.

How else can we power electrical appliances? That's right, from a battery. A battery works by providing electrons with a solution in which they can move around. Have you ever noticed that some batteries have a copper end that is positive (shown with a plus [+] sign) and another end that is negative (shown with a minus [-] sign)? Zinc is a metal that likes to give its electrons to copper. Usually, zinc just gives its electrons to copper and then the process stops. However, if you provide the electrons with a solution (called an electrolyte) to help them move to the copper, and you give the electrons a wire in which they can move from the copper back to the zinc, you can produce a circuit and a flowing path of electrical energy. (Note: Conventional current flows from positive to negative, so from the copper, through the wire, back to the zinc. The electrons actually flow negative to positive.)

A circuit is a complete path of electrical energy. This means that electrical energy or charge is produced or stored somewhere ( voltage) and has a path for the charge to flow (or current). Another part of a circuit is a resistance, such as a light bulb. Electrical engineers create circuits to help electrical energy perform work, such as lighting a room or keeping food cold. An appliance, light bulb or almost any device that uses electrical energy is a resistance. A resistance prevents or slows an electrical current or charge from moving. When electrical current flows through a source of resistance, it can be changed into light or heat or sound. Even though you cannot see it, the light bulb or appliance slows down the electrical charge.

Electrical engineers help develop the many modern products and appliances that require electrical energy. Electrical engineers also help create the technology used to generate the electrical energy in power plants in the first place. These engineers know a lot about circuits and they continually work to find better ways to store electrical charge and generate electrical current without using nonrenewable fossil fuels such as coal and oil. These electrical engineers are very important in almost everything we do! Essentially, electrical engineers create improvements for society and help save our planet for future generations. Today, we are going to be electrical engineers and learn more about how electrical energy works in a circuit. We are also going to look at generating electrical current from the energy stored in a potato! Do you think we can light a bulb with a potato? Let's try it!

Procedure

Background

How does a potato battery work? The copper (Cu) atoms attract electrons more than the zinc (Zn) atoms. If you place a strip of copper and a strip of zinc in contact with each other, many electrons pass from the zinc to the copper. As they concentrate on the copper, the electrons repel each other. When the force of repulsion between electrons and the force of attraction of electrons to the copper become equalized, the flow of electrons stops. Unfortunately it is not possible to take advantage of this behavior to produce electricity because the flow of charges stops almost immediately. On the other hand, if you bathe the two strips in a conductive solution, and connect them externally with a wire, the reactions between the electrodes and the solution continually furnish the circuit with charges. In this way, the process that produces the electrical energy continues and becomes useful. In a conductive solution, the charge is carried by ions that move through the solution. In the solid state, the ions are not able to move around freely. However, once they are dissolved in water, they become completely mobile. They can "swim" around in the water and thus can respond to an electric current from a battery. That current supplies electrons that cause positive ions to flow in one direction and negative ions to flow in the opposite direction. The ions carry electrical charge from one electrode to another, completing the electrical circuit.

For a conductive solution, use any electrolyte, whether it is an acid, base or salt solution. An electrolyte is a substance whose aqueous solution contains various ions and thus conducts electricity. Therefore, the more free ions a solution has, the better conductor it will be. Many fruits and vegetables contain juices rich in ions and are therefore good electrical conductors.

Like any battery, a potato battery has a limited life span. The electrodes undergo chemical reactions that block the flow of electricity. The electromotive force diminishes and the battery stops working. Usually, what happens is the production of hydrogen at the copper electrode and the zinc electrode acquires deposits of oxides that act as a barrier between the metal and the electrolyte. This is referred to as the electrodes being polarized. To achieve a longer life and higher voltages and current flows, it is necessary to use electrolytes better suited for the purpose. Commercial batteries, apart from their normal electrolyte, contain chemicals with an affinity for hydrogen, which combine with the hydrogen before it can polarize the electrodes.

Before the Activity

With the Students

1. Divide the class into teams of two or three students each. Hand out the materials.

2. Direct groups to carefully place the zinc nails and copper pennies into the potato. Make sure the two different metals do not touch each other in the potato (see Figure 1).

3. Connect one alligator clip to the end of the penny sticking out of the potato and another alligator clip to the end of the nail sticking out of the potato (see Figure 1).

Figure 1. Placement of the nail, penny and alligator clips.

1. (If you have a multimeter) Tell students that a multimeter is an instrument that measures current, voltage and resistance of a circuit, and is a tool (created by and) often used by engineers. Set the multimeter on a low "DC volts" scale for voltage and "DC milliamps" for current, so students can see the charge that one potato can produce. Expect the potato to produce just less than 1 volt. Encourage students to convert the decimal readout from the multimeter to a fraction (for example, 0.82 volts = 82/100 volts).

2. Have the students figure out how many potatoes they need to light their LED clock (or clock). For example, if their potato produces a voltage of 0.8 volts, then they may need two potatoes to power a 1.5 voltage LED.

3. Have students experiment to figure out how to connect two potatoes together. To connect two potatoes in series (to add more voltage), place a penny and nail into a second potato, and connect the wire from the zinc nail in the first potato to the copper penny in the second. Then, add a third wire to the zinc nail in the second potato. Always remember to connect the copper (positive) end of the potato (battery) to the zinc (negative) end of the next potato (see Figure 2).

Figure 2. Activity setup to create a potato battery to power an LED clock.

1. Expect two potatoes in series to be able to light an LED; however, you might need three. Show students how to connect the LEDs to the potato in the correct manner, that is, the positive end of the LED to the negative end of the potato battery (zinc nail) and the negative end of the LED to the positive end of the potato battery (copper penny).

2. Have students discuss how the potatoes provide the electrolyte (solution) for the chemical battery to work. Ask for suggestions of other foods we could try (for example, lemons, berries, apples).

3. Ask students to complete the worksheet either individually or in pairs. After they finish, have them compare answers with a peer or another pair, giving all students time to finish.

Vocabulary/Definitions

conductor: An object that allows the transfer of electrons.

current: The movement of electrons.

electrical energy: Energy produced through the movement of electrons (voltage X current).

electrolyte: A solution that conducts electricity.

energy: The ability to do work.

insulator: An object that inhibits the transfer of electrons.

resistance: Objects or substances that prevent the passage of a steady electric current.

voltage: The amount of energy produced.

Assessment

Pre-Activity Assessment

Brainstorming: In small groups, have students engage in open discussion. Remind them that no idea or suggestion is "silly." All ideas should be respectfully heard. Take an uncritical position, encourage wild ideas and discourage criticism of ideas. Ask students how many items they can think of that run on batteries. As a class, record their ideas on the board.

Quick Poll: Before the activity begins, ask the class a question and tally their responses on the board. Ask: Can we get electrical energy from a fruit or vegetable?

Activity Embedded Assessment

Worksheet /Pairs Check: Have students work individually or in pairs on the Make a Battery Worksheet. After they finish, have them compare answers with a peer or another pair, giving all students time to finish the worksheet.

Hypothesize: Ask each group what would happen if we added more potatoes in a row to our circuits? (Answer: Adding more potatoes in a row is the same as adding batteries in a row. The voltage of each piece of potato is added up. Thus, the voltage of our circuit would increase. On the other hand, the current of our circuit would not increase. Current is not dependent on how many potatoes but is related to the size of each potato individually.)

Post-Activity Assessment

Problem Solving: Present the class with the following math problems and ask students to calculate how many of each vegetable or fruit are needed to light the bulb.

If a lemon produces 1 Volt of energy, how many lemons would you need to light a 2 Volt light bulb? (Answer: 2)

If a potato produces 0.8 Volts of energy, how many potatoes would you need to light a 1.5 Volt light bulb? (Answer: 2)

If a potato produces 0.8 Volts of energy, how many potatoes would you need to light a 3 Volt digital clock? (Answer: 4)

If you have a lemon that produces 1 Volt of energy and an apple that produces 1 Volt of energy, can you light a 3 Volt clock? (Answer: No, you would need one more lemon or apple.)

Diagramming: Engineers must understand how circuits work in order to develop cool new technologies. Draw a picture of your potato battery. Label the battery (voltage) and the resistance (light bulb). Draw an arrow to show the current flow (from the copper end to the zinc end). List two cool products that an engineer could develop that run off a fruit battery.

Troubleshooting Tips

If the LED clock, light or small light bulbs do not work, check the setup of the potato battery. Perhaps the ends are not all connected from negative to positive, or perhaps there is not enough potato voltage. Check the voltage of the potato using a multimeter or voltmeter. Another possibility is having enough voltage, but not enough current to light the bulb, which is why it is recommended to use only very low-volt LED clocks or bulbs. Also, try using more potatoes (i.e., 5 potato halves) to strengthen conductivity. Try different LED colors (for example, the blue LED may work better than the red).

Lemons and oranges also work well for this activity. They work best if you first roll them on a table top, which breaks down the cells inside so more juice flows through the fruit (current).

Some people have more conduction success using copper strips instead of copper pennies (can also wrap the pennies in copper ribbon).

Soaking the potatoes in Gatorade overnight can make them more conductive.

Activity Extensions

At activity end, before students disassemble their potato batteries, it is fun to have the entire class connect their fruit batteries in series, making "a serious tater circle."

Have students try the activity again using different fruits or vegetables! Many fruits and vegetables work, such as lemons, limes, apples and carrots. Have students compare and contrast the performance of different fruits and vegetables.

Have students complete the activity again using an electrolyte solution, such as salt water or vinegar. Have them compare and contrast the performance of different electrolyte solutions.

To add a math component, have students use the multimeter to compare the flow of electricity for several different fruits as well as to the total amount of fruits used. Ask them to graph the results and hypothesize what is happening.

Activity Scaling

Have more advanced students experiment with parallel and series configurations using different numbers of potatoes.

References

Dictionary.com. Lexico Publishing Group, LLC. Accessed September 28, 2005. (Source of some vocabulary definitions, with some adaptation) http://www.dictionary.com

Phillips, W.D. Chapter 2P: Using a Multimeter. Design Electronics (online textbook) DOCTRONICS Educational Publishing, UK. Accessed September 28, 2005. (Good design, technology and electronics resources.) http://www.doctronics.co.uk/meter.htm

Copyright © 2005 by Regents of the University of Colorado

Contributors Sharon D. Perez-Suarez; Jeff Lyng; Malinda Schaefer Zarske; Denise W. Carlson; Janet Yowell

Supporting Program Integrated Teaching and Learning Program, College of Engineering, University of Colorado Boulder

Acknowledgements

The contents of this digital library curriculum were developed under grants from the Fund for the Improvement of Postsecondary Education (FIPSE), U.S. Department of Education, and the National Science Foundation (GK-12 grant no. 0338326). However, these contents do not necessarily represent the policies of the Department of Education or National Science Foundation, and you should not assume endorsement by the federal government.

Last modified: July 9, 2020

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Students use potatoes to light an LED clock (or light bulb) as they learn how a battery works in a simple circuit and how chemical energy changes to electrical energy. As they learn more about electrical energy, they better understand the concepts of voltage, current and resistance.

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I chose this lesson because it's fun, and I think students would really enjoy it. It's a great introduction to physics, and it allows students to create their own catapult which is neat. They can then test their catapults and learn from the outcome. This is a great example of experiential learning.
-Taylor Sciubba

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Posted on by ASEE

(Lesson Courtesy COSI Columbus - The Center for Science and Industry). Level: Grades 4 - 8. Time required: 30 to 50 minutes. Click HERE for PDF of activity. Click HERE for version developed by Ohio State University engineering graduate students and Maize Elementary teachers

Overview

This simple catapult activity for students in grades 4 - 8 teaches them how energy is transferred when a plastic spoon is pulled back, then released, rocketing its payload - a single marshmallow.

Background

What's going on? The plastic spoon has an inherent elasticity, which means it will return to its original shape after being deformed. Rubber bands and other elastic objects also have this property. When the spoon is deformed, the force used to cause that deformation is "stored" in the spoon as elastic potential energy. When the spoon is released, the elastic potential energy changes to kinetic energy as the spoon returns to its original shape, carrying the marshmallow along with it. The marshmallow continues to move after the spoon has stopped due to its inertia.

Catapult Information

(from the Museum of Ancient Inventions, Smith College)

The catapult was an ancient siege machine that could hurl heavy objects or shoot arrows with great force and for considerable distances. Some catapults could throw stones weighing as much as 350 pounds for distances greater than 300 feet.

The Greek Dionysius the Elder of Syracuse, who was looking to develop a new type of weapon, invented the catapult about 400 BCE. Thereafter, it became a key weapon in warfare and remained so up through mediaeval times. Two major catapults evolved from Dionysius's invention: the double-armed machine, or ballista, used for shooting arrows, and the single-armed catapult designed for hurling large objects. Although the Romans added wheels to both types of catapult for maneuverability, very little in the design of the machine changed.The reconstruction shown here is of a single-armed stone-hurling catapult, approximately two feet long and one-and-a-half feet tall. Its hurling arm is driven by a cocked, winch-pulled cord.

Standards (Ohio)

Physical Science: 1.6, 3.3, 3.4, 7.2, 7.4

Vocabulary

elasticity, potential energy, kinetic energy, deflection angle

Materials

Plastic spoon

1-2 bags of miniature marshmallows

marking pens

tape measure or meter stick

masking tape

protractor

safety goggles

Procedure
Instruction for teachers:
Set up the classroom so that you have at least 20 feet of open space in front of the launching area for a landing area. Have students put on goggles, then align teams of 3-4 students along one side of a set of long tables or a counter so the catapults will be aimed across the room.

Distribute to each group safety goggles, spoons, marshmallows, protractors, and lengths of masking tape.
Instructions for students:
1. Prepare your catapult by taping a spoon firmly against the edge of a table, perpendicular to the tabletop with the bowl of the spoon facing toward the table.

2. Mark your marshmallows for identification with a pen, using your group initials.

3. Test the setup of your catapult and marshmallow: Hold the marshmallow in the bowl of the spoon. Use your thumb to help anchor the spoon handle against the table.

4. Practice launch: Keeping the end of the spoon handle against the table, launching the marshmallow across the room. (Don't point it at anyone!)

5. Experiment with pulling the spoon back farther to change the angle - what are the results?

Now, determine the best deflection angle - how far you pull back the spoon - to launch the marshmallow the farthest possible distance. Decide how much to deflect the spoon, using a protractor to measure the angle between the spoon and the table. Record the measurements of your deflection angle on a sheet of paper, then launch your marshmallow and measure the distance it travels. Repeat this two more times and compute the average of the three.

6. Now, change the deflection angle of the catapult and repeat. Record the average distance for three separate different catapult angles. Record your results. What angle between the spoon and table launches the marshmallow the farthest?

7. Based on your data, predict the optimum deflection angle.

8. Hold a class contest to find out who can make a marshmallow fly the farthest.

Extensions

Ask the class what would happen if they changed the weight/size of the marshmallow - and how could they do that? Which other techniques could makes the marshmallow go farther? Higher?

Spoons may be made of several different types of plastic. Bring in other plastic spoons and try this experiment. Compare and contrast the results. Look up the properties of the different types of plastic and relate these properties to the results.

For homework, challenge students to come up with their own catapult design - still using the marshmallow load - then allow them to construct, test, and demonstrate their models in class the next day. What innovative solutions did each group devise? Have students evaluate their results and those of their classmates.

Assign students to research the history of catapults. When were they used, and for what purposes?

Resources

More ancient inventions at Smith College's online Museum of Ancient Inventions
http://www.middle-ages.org.uk/catapults.htm http://www.medieval-castle-siege-weapons.com/medieval-catapults.html
Filed under: Class Activities, Grades 6-8, Grades K-5, Grades K-5, Lesson Plans

Tags: catapult, Class Activities, forces and motion, Fun & Games, Grades 4 - 8, Grades K-5, Newton's Laws, Physical Science, Physics, trebuchet

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eGFI - For Teachers " Activity: Catapult Marshmallow Launch

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Posted on by ASEE (Lesson Courtesy COSI Columbus - The Center for Science and Industry). Level: Grades 4 - 8. Time required: 30 to 50 minutes. Click HERE for PDF of activity.

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Sara Kashatus
This lesson would be great to use in  a classroom because it is a fun way to integrate science with a book that students love. I remember doing a lesson like this when I was young. It's a great way to develop student's critical thinking skills and let them have fun at the same time.

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My boys are not big on drawing and I often struggle to get them to embrace their inner artists. But add in a lego car and some strings to drive it up a wall and suddenly drawing is super cool! Lego car art combines engineering, Lego and art for fun that is irresistible to even the most reluctant artist! Keeping the A in STEAM!

Disclaimer: This post uses affiliate links. At no cost to you, if you purchase after clicking on one of my links I get a small commission. Thank you in advance for your support of STEAM Powered Family.

To accomplish this feat took a bit of engineering and trial and error.

First we constructed the car with pieces from our Creative Lego Box. It's a simple design, essentially a rectangle with cross bars that we attached the axles of the wheels to.

Then we added our Lego man on his seat, making sure to leave a 4×4 gap. This is the space for the marker.

Then we added the circle pieces with the hole in the middle. These became our hitch points for our strings. We found it took a bit of experimenting to find the right balance and angle to place these hitch points. We tried placing them on the top at the front. Then on the sides, both top and bottom, but we found that for the angles we were working at, at the front on the bottom worked the best and caused the least amount of "spin outs".

Our wall was our much loved easel. And the feed points for the string were clips that were sturdy enough to handle the pull of the strings. They worked perfectly!

I made handles for the strings (tied the string around a 2×8 brick) but the boys preferred to hold the strings and ignored the handles so I took them off.

We used Pipsqueaks markers which are shorter and worked better for maintaining the balance of the car as it moved about. I added a layer of tape just to get a really snug fit. I'm not sure it was really necessary, especially once the boys got the hang of manipulating the car with the strings, but if you have younger kids the snug fit is helpful.

In the end our Lego man drove his little car around leaving all sorts of great designs. I used a large piece of card stock so the boys had lots of room to cruise around.

The boys both had so much fun and it was great to see how they had to really slow down and take their time. If they moved too quickly the car would "spin out" and come off the wall. Or if they pulled too hard the hitch points would pop off the car. Slow and steady was the name of the game.

I'm planning on leaving it up for a while so the boys can practice, it's not easy. There is a lot of technique and skill required to get that Lego man to drive where you want him to go. Our OT suggested that core work and vertical surface work would really help my boys with their fine motor skills and although this is a little different, I think there are a lot of benefits to them mastering this type of skill.

To do a little extra vertical work I had Preston hold the car in his hand and drive it around a bit too. I had him do this with both hands so he could work both sides of his body and develop some skills that are a struggle for him.

As both boys get better at this, I might started giving them challenges like trying to write letters or shapes, or turn it into a game where they need to traverse a maze. For now though they are having fun creating and being ARTISTS and that is a beautiful thing! We never want to forget the A in STEAM!

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Lego Car Art - Lego, Engineering and Art Combine for Creative FUN on a Vertical Surface!

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My boys are not big on drawing and I often struggle to get them to embrace their inner artists. But add in a lego car and some strings to drive it up a wall and suddenly drawing is super cool! Lego car art combines engineering, Lego and art for fun that is irresistible to even the most reluctant artist!

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I choose this lesson because it looks really fun and I feel like all students would be engaged.
-Ally Green

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What's cheaper than a Peep? Jelly beans! They're everywhere and after Easter, stores mark them half off. I have 3 Easter science activities to share with you today that are awesome for your elementary students. Keep it simple or take them to the next level!

Solubility

The first activity addresses solutions, solutes, solvents, and concentration. There are several ways you can do this, but here is one of them.
Use different amounts of warm water (100ml and 25ml) to dissolve 2 jelly bean candy shells. (A little white part will remain that you can toss.) You can use *strong* baggies or cups for the water. Identify how the transparency of the color depends on the concentration.

Physical Properties

Identify the physical properties of a jelly bean. Mix them together in a group. Do the physical properties of the jelly bean change? Place the jelly bean in water. How do the physical properties of the jelly bean change?

Jelly Bean Towers

Provide each student with 10 toothpicks and 10 jelly beans. The challenge to create the tallest stable tower possible. There must be a jelly bean at the top of the tower. Identify weak levels and strong levels. Provide students an opportunity to draw their designs and refine them.

Happy Easter!

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Easter Science Activities with Jelly Beans

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What's cheaper than a Peep? Jelly beans! They're everywhere and after Easter, stores mark them half off. I have 3 Easter science activities to share with you today that are awesome for your elementary students. Keep it simple or take them to the next level! The first activity addresses solutions, solutes, solvents, and concentration.

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I chose this lesson because I thought the scientific process was so cool. It can really get students thinking. It also allows students to be creative in that they choose the design.
-Taylor Sciubba
I'm a little behind because I started on my phone and it wasn't working. Sorry!

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Make plastic from milk? It seems like some sort of lactose intolerant horror story, but it's actually a really cool science process. Create your own toys, beads, jewelry, and more, with ingredients you have right now in your kitchen. It's so easy and super cool!

Turn Milk Into Plastic Toys!
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Also known as casein plastic, this process has been used for over 100 years and is the way they used to make plastics before 1945 when synthetic plastics were introduced. Even royalty wore jewelry made from milk plastic many years ago. How cool is that?

With this simple process you can make toys, beads, jewelry, decorative pieces and more. This is a great, budget friendly experiment, with spectacular results that will have your students pumped with excitement for science!

A stove top or microwave to warm the milk
Milk (we used 2%, lower fat content is better)
White Vinegar or Lemon Juice
Bowl
Spoon
Strainer (or can create your own using cheese cloth or similar)
Paper towel
Molds (we loved using our Lego minifigures and Dinosaur molds) or other tools for shaping.

Time: 30 to 90 minutes for the experiment, then 2 days for drying. Add in a little extra time for painting once dry!

Measure out 1 cup of milk (you can also use chocolate milk and the end result smells amazing!), this makes about 4 minifigures or 4 dinosaurs. Heat on the stove top in a pot or in the microwave in a heat resistant bowl. You want it to just start steaming. Remove from the heat. Add 4 tsp of vinegar or lemon juice and stir gently.

The amount of vinegar is not exact. We used 4 tbsp by accident and it was fine, just made for a more intense vinegar smell!

You will notice that it immediately begins to curdle. You're making curds and whey!

Stir gently for approximately one minute for the full reaction to finish and all the curds to form. Don't stir aggressively. Be gentle.

Strain off the whey using a strainer or you can use cheese cloth (or similar). Let drip for a few minutes until most of the liquid has drained off. Gently smoosh the curds around in the strainer if needed.

Now remove the curds and place them on a few layers of paper towel. Carefully pat and squish to remove more liquid. You may need to replace the paper towel and repeat a few times. The goal is to remove as much liquid as possible.

You will notice it is kind of crumbly and squishy, but you can smoosh and shape it.

Now you can put it in your molds at this point but we discovered that if you put the curds in a jar or bowl, soaking in vinegar for an hour, you will get a much smoother final product. Plus they are more white if you do this extra step. If you do the extra vinegar soak, once the hour is up, repeat the straining, and paper towel drying process again. This time you will notice it is smoother in texture and no longer crumbly.

During the vinegar soak you can add some food colouring if you want. Just put a few drops in with the vinegar while it is soaking and it will colour the curds. Or make yours glow in the dark with our favourite trick!

Now squish it into your molds. We used silicone molds to make Lego minifigs and dinosaurs.

You can also shape it by hand. Roll it to create beads, then use a skewer to put a hole through it before setting it aside to dry. Or flatten it and use some cookie cutters.

The drying process takes time, approximately 2 days depending on your natural humidity levels and how much moisture you removed with the paper towels. But you can remove it from the silicone molds after 24 hours and this will help speed up the drying time.

Once dry, clean up the edges a bit if necessary, just like you would with any other casting. You can do this with just your fingers, a piece of sand paper or other tools. It will be hard plastic now, so it might take a little extra work!

You can paint the final products with either acrylic paints or markers. I used acrylic paints and a sharpie for the faces on mine. Spray them with a clear coat to give them a nice shine once you are finished.

VOILA! Who knew it was so easy, and so much fun, to make plastic from milk!

Our oldest Milk Plastic Toys are over 2 years old now and show no signs of degrading. We haven't done any experiments yet to see if they might break down with moisture, or heat, or sun, but that might go on the books for a future study. They are definitely highly durable!

This is a chemistry experiment working with polymers. Polymers are molecules that have formed a regular chain structure. Milk contains molecules of a protein called Casein. During this reaction between warm milk and acid the casein molecules unfold and form long chains called a polymer. The polymer can be molded and shaped which makes it a plastic. In this case it's called casein plastic or milk plastic because of the type of molecules that created the plastic.

More STEM activities

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Make Milk Plastic in the Kitchen Chemistry Project for Kids

# data[].attributes.attachment_link.description
Make plastic from milk? It seems like some sort of lactose intolerant horror story, but it's actually a really cool science process. Create your own toys, beads, jewelry, and more, with ingredients you have right now in your kitchen. It's so easy and super cool! Disclaimer: This article may contain commission or affiliate links.

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This lesson would be my go to due to how both simplistic and entertaining the lesson could be, especially if the lesson is combined with a hypothesis type of activity.
-Austin Miller
https://creativefamilyfun.net/hot-chocolate-science/

# data[].attributes.body
I think this one is my favorite out of the two because not only are the kids learning about making predictions, but then they get to also enjoy a nice cup of hot cocoa.

# data[].attributes.attachment_link.readable_text
I love my girls' natural curiosity when it comes to science. So, when my daughter asked me "Can we do a hot chocolate science experiment?" I knew it was time to get creative.

Working together, we came up with an amazing STEM activity.

When we make instant hot chocolate, we dissolve the contents of the packet into hot water. We decided to find out if temperature affected the speed that it dissolves.

Let's get started!

Disclosure: There are Amazon Affiliate and other affiliate links in this article which means, at no additional cost to you, we could receive compensation for our recommendations. You can read our full disclosure policy on our Disclosure Page for more details.

Supplies Needed for Your Hot Chocolate Science Project

First we needed to gather our supplies. Luckily most of the items were already in our kitchen.

Here's what you'll need:

Three heat-proof mugs
Three packets of instant hot chocolate
Measuring cup
Water
Spoons
Stopwatch or timer
Notebook for recording your results.

How to Do Your Hot Chocolate Science Experiment

We started our experiment by making a prediction. Which temperature of water would dissolve the hot chocolate the quickest?

The girls made their prediction (they chose hot) and then it was time to experiment.

We started by emptying our hot chocolate packets into our mugs, one packet per mug. Then we moved on to testing the different temperatures of water.

We tested each temperature, one at a time. We were very vague with our temperatures, using ice cold water, room temperature water, and hot water. You can always add a kitchen thermometer to measure the temperature of the water to add an extra measurement element to your experiment.

My girls took turns measuring the water, stirring, and operating the stopwatch. We used the digital stopwatch on my phone to time how long the hot chocolate took to dissolve.

For each cup, we measured 6 oz. of water. We used cold water from our refrigerator over ice, lukewarm water from the tap, and I did my grown-up duty and heated water in the microwave for the last mug.

Once the water was added to a mug, one girl started the stopwatch and the other started stirring. We stopped the stopwatch as soon as we saw the hot chocolate had dissolved.

Does Hot Chocolate Dissolve Faster in Hot Water or Cold Water?

We started with the ice cold water. My oldest daughter was in charge of the stirring. She stirred and stirred and stirred some more. It wouldn't dissolve. Eventually, we made the decision to stop after three minutes. You can see the results above. Disgusting!

We moved on to the room temperature water, which clocked in at 1 minute 38 seconds. And, then the hot water, which only took 28 seconds.

The results: hot water takes the least amount of time. We predicted that because the instructions said to use hot water when we made hot chocolate. (And, it's called hot chocolate after all...) But, now we know why we need to use hot water.

Why Does Hot Chocolate Powder Dissolve Faster in Hot Water?

Hot water has more energy than cold water. With more energy, the molecules in the water move faster breaking down the hot chocolate mix quicker.

Once we finished writing our results, we unceremoniously dumped the cold water hot chocolate sludge down the kitchen sink. Ick.

What happened to the other two mugs? They were topped with a dollop of whipped cream and enjoyed!

Our hot chocolate science experiment and turned out great!

More STEAM Activities to Try
Hockey Science Christmas Science: Grow the Grinch's Heart Edible STEM Projects for Kids Marshmallow Engineering STEAM Building Challenge 28 Awesome STEM Challenges for the Elementary Classroom at Teach Junkie
STEM Activities for Kids in the Kitchen at iGame Mom

Do more science at home:

We love Green Kid Crafts boxes because they provide easy, ready-to-do STEM activities we can try at home. You'll receive easy-to-follow instructions plus the supplies that you need for up to 6 activities. You can get a monthly subscription or buy a single themed box. If you enjoyed our hot chocolate science experiment, you may enjoy the Kitchen Science or the monthly Discovery Box subscription.

Click here for the Kitchen Science box.

Click here for the monthly Discovery Box subscription.

Are you looking for more activities?

Join our fun Facebook community, Creative Family Fun for Busy Families, for daily activities that are great for kids and families. We'll chat, share, and have fun. It's a safe and private place to share idea for family and kids activities. I'd love for you to join me! Just click the link below, request to join, and answer the questions (they're easy, I promise). Come join the fun! Join the Creative Family Fun for Busy Families community here.

The following two tabs change content below.

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This hot chocolate science experiment is a fun way to learn about how temperature affects the rate at which hot chocolate dissolves.

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I picked this lesson because I love how it fun and seasonal while learning about science. I think it is a perfect activity to learn about solubility by dissolving the candy shells. Also, the jelly bean tower is a great idea. Students must think critically to create the most stable tower. - Jackie Flick

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What's cheaper than a Peep? Jelly beans! They're everywhere and after Easter, stores mark them half off. I have 3 Easter science activities to share with you today that are awesome for your elementary students. Keep it simple or take them to the next level!

Solubility

The first activity addresses solutions, solutes, solvents, and concentration. There are several ways you can do this, but here is one of them.
Use different amounts of warm water (100ml and 25ml) to dissolve 2 jelly bean candy shells. (A little white part will remain that you can toss.) You can use *strong* baggies or cups for the water. Identify how the transparency of the color depends on the concentration.

Physical Properties

Identify the physical properties of a jelly bean. Mix them together in a group. Do the physical properties of the jelly bean change? Place the jelly bean in water. How do the physical properties of the jelly bean change?

Jelly Bean Towers

Provide each student with 10 toothpicks and 10 jelly beans. The challenge to create the tallest stable tower possible. There must be a jelly bean at the top of the tower. Identify weak levels and strong levels. Provide students an opportunity to draw their designs and refine them.

Happy Easter!

# data[].attributes.attachment_link.title
Easter Science Activities with Jelly Beans

# data[].attributes.attachment_link.description
What's cheaper than a Peep? Jelly beans! They're everywhere and after Easter, stores mark them half off. I have 3 Easter science activities to share with you today that are awesome for your elementary students. Keep it simple or take them to the next level! The first activity addresses solutions, solutes, solvents, and concentration.

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I chose this lesson because it offers two different science lessons. One allows students to build using jelly beans. The students have to create the strongest and tallest structure with jelly beans! The other lesson includes solubility which is a very fun concept for kids!
-Alexis Cancila

# data[].attributes.attachment_link.readable_text
What's cheaper than a Peep? Jelly beans! They're everywhere and after Easter, stores mark them half off. I have 3 Easter science activities to share with you today that are awesome for your elementary students. Keep it simple or take them to the next level!

Solubility

The first activity addresses solutions, solutes, solvents, and concentration. There are several ways you can do this, but here is one of them.
Use different amounts of warm water (100ml and 25ml) to dissolve 2 jelly bean candy shells. (A little white part will remain that you can toss.) You can use *strong* baggies or cups for the water. Identify how the transparency of the color depends on the concentration.

Physical Properties

Identify the physical properties of a jelly bean. Mix them together in a group. Do the physical properties of the jelly bean change? Place the jelly bean in water. How do the physical properties of the jelly bean change?

Jelly Bean Towers

Provide each student with 10 toothpicks and 10 jelly beans. The challenge to create the tallest stable tower possible. There must be a jelly bean at the top of the tower. Identify weak levels and strong levels. Provide students an opportunity to draw their designs and refine them.

Happy Easter!

# data[].attributes.attachment_link.title
Easter Science Activities with Jelly Beans

# data[].attributes.attachment_link.description
What's cheaper than a Peep? Jelly beans! They're everywhere and after Easter, stores mark them half off. I have 3 Easter science activities to share with you today that are awesome for your elementary students. Keep it simple or take them to the next level! The first activity addresses solutions, solutes, solvents, and concentration.

# data[].attributes.body
I would use this little experiment in my classroom because it is a really easy way to show students how different substances change when they are emerged in heat! It is also fun because what kids doesn't like hot chocolate! -Victoria Malpica

# data[].attributes.attachment_link.readable_text
I love my girls' natural curiosity when it comes to science. So, when my daughter asked me "Can we do a hot chocolate science experiment?" I knew it was time to get creative.

Working together, we came up with an amazing STEM activity.

When we make instant hot chocolate, we dissolve the contents of the packet into hot water. We decided to find out if temperature affected the speed that it dissolves.

Let's get started!

Disclosure: There are Amazon Affiliate and other affiliate links in this article which means, at no additional cost to you, we could receive compensation for our recommendations. You can read our full disclosure policy on our Disclosure Page for more details.

Supplies Needed for Your Hot Chocolate Science Project

First we needed to gather our supplies. Luckily most of the items were already in our kitchen.

Here's what you'll need:

Three heat-proof mugs
Three packets of instant hot chocolate
Measuring cup
Water
Spoons
Stopwatch or timer
Notebook for recording your results.

How to Do Your Hot Chocolate Science Experiment

We started our experiment by making a prediction. Which temperature of water would dissolve the hot chocolate the quickest?

The girls made their prediction (they chose hot) and then it was time to experiment.

We started by emptying our hot chocolate packets into our mugs, one packet per mug. Then we moved on to testing the different temperatures of water.

We tested each temperature, one at a time. We were very vague with our temperatures, using ice cold water, room temperature water, and hot water. You can always add a kitchen thermometer to measure the temperature of the water to add an extra measurement element to your experiment.

My girls took turns measuring the water, stirring, and operating the stopwatch. We used the digital stopwatch on my phone to time how long the hot chocolate took to dissolve.

For each cup, we measured 6 oz. of water. We used cold water from our refrigerator over ice, lukewarm water from the tap, and I did my grown-up duty and heated water in the microwave for the last mug.

Once the water was added to a mug, one girl started the stopwatch and the other started stirring. We stopped the stopwatch as soon as we saw the hot chocolate had dissolved.

Does Hot Chocolate Dissolve Faster in Hot Water or Cold Water?

We started with the ice cold water. My oldest daughter was in charge of the stirring. She stirred and stirred and stirred some more. It wouldn't dissolve. Eventually, we made the decision to stop after three minutes. You can see the results above. Disgusting!

We moved on to the room temperature water, which clocked in at 1 minute 38 seconds. And, then the hot water, which only took 28 seconds.

The results: hot water takes the least amount of time. We predicted that because the instructions said to use hot water when we made hot chocolate. (And, it's called hot chocolate after all...) But, now we know why we need to use hot water.

Why Does Hot Chocolate Powder Dissolve Faster in Hot Water?

Hot water has more energy than cold water. With more energy, the molecules in the water move faster breaking down the hot chocolate mix quicker.

Once we finished writing our results, we unceremoniously dumped the cold water hot chocolate sludge down the kitchen sink. Ick.

What happened to the other two mugs? They were topped with a dollop of whipped cream and enjoyed!

Our hot chocolate science experiment and turned out great!

More STEAM Activities to Try
Hockey Science Christmas Science: Grow the Grinch's Heart Edible STEM Projects for Kids Marshmallow Engineering STEAM Building Challenge 28 Awesome STEM Challenges for the Elementary Classroom at Teach Junkie
STEM Activities for Kids in the Kitchen at iGame Mom

Do more science at home:

We love Green Kid Crafts boxes because they provide easy, ready-to-do STEM activities we can try at home. You'll receive easy-to-follow instructions plus the supplies that you need for up to 6 activities. You can get a monthly subscription or buy a single themed box. If you enjoyed our hot chocolate science experiment, you may enjoy the Kitchen Science or the monthly Discovery Box subscription.

Click here for the Kitchen Science box.

Click here for the monthly Discovery Box subscription.

Are you looking for more activities?

Join our fun Facebook community, Creative Family Fun for Busy Families, for daily activities that are great for kids and families. We'll chat, share, and have fun. It's a safe and private place to share idea for family and kids activities. I'd love for you to join me! Just click the link below, request to join, and answer the questions (they're easy, I promise). Come join the fun! Join the Creative Family Fun for Busy Families community here.

The following two tabs change content below.

# data[].attributes.attachment_link.description
This hot chocolate science experiment is a fun way to learn about how temperature affects the rate at which hot chocolate dissolves.

# data[].attributes.body
I really liked both lessons, and I would do both, but I have to choose one. I chose this lesson because it is very fun and interactive for students. It is a very easy way to show that with more energy, molecules in the water can break down the hot chocolate mix faster.
~Sara Flood

# data[].attributes.attachment_link.readable_text
I love my girls' natural curiosity when it comes to science. So, when my daughter asked me "Can we do a hot chocolate science experiment?" I knew it was time to get creative.

Working together, we came up with an amazing STEM activity.

When we make instant hot chocolate, we dissolve the contents of the packet into hot water. We decided to find out if temperature affected the speed that it dissolves.

Let's get started!

Disclosure: There are Amazon Affiliate and other affiliate links in this article which means, at no additional cost to you, we could receive compensation for our recommendations. You can read our full disclosure policy on our Disclosure Page for more details.

Supplies Needed for Your Hot Chocolate Science Project

First we needed to gather our supplies. Luckily most of the items were already in our kitchen.

Here's what you'll need:

Three heat-proof mugs
Three packets of instant hot chocolate
Measuring cup
Water
Spoons
Stopwatch or timer
Notebook for recording your results.

How to Do Your Hot Chocolate Science Experiment

We started our experiment by making a prediction. Which temperature of water would dissolve the hot chocolate the quickest?

The girls made their prediction (they chose hot) and then it was time to experiment.

We started by emptying our hot chocolate packets into our mugs, one packet per mug. Then we moved on to testing the different temperatures of water.

We tested each temperature, one at a time. We were very vague with our temperatures, using ice cold water, room temperature water, and hot water. You can always add a kitchen thermometer to measure the temperature of the water to add an extra measurement element to your experiment.

My girls took turns measuring the water, stirring, and operating the stopwatch. We used the digital stopwatch on my phone to time how long the hot chocolate took to dissolve.

For each cup, we measured 6 oz. of water. We used cold water from our refrigerator over ice, lukewarm water from the tap, and I did my grown-up duty and heated water in the microwave for the last mug.

Once the water was added to a mug, one girl started the stopwatch and the other started stirring. We stopped the stopwatch as soon as we saw the hot chocolate had dissolved.

Does Hot Chocolate Dissolve Faster in Hot Water or Cold Water?

We started with the ice cold water. My oldest daughter was in charge of the stirring. She stirred and stirred and stirred some more. It wouldn't dissolve. Eventually, we made the decision to stop after three minutes. You can see the results above. Disgusting!

We moved on to the room temperature water, which clocked in at 1 minute 38 seconds. And, then the hot water, which only took 28 seconds.

The results: hot water takes the least amount of time. We predicted that because the instructions said to use hot water when we made hot chocolate. (And, it's called hot chocolate after all...) But, now we know why we need to use hot water.

Why Does Hot Chocolate Powder Dissolve Faster in Hot Water?

Hot water has more energy than cold water. With more energy, the molecules in the water move faster breaking down the hot chocolate mix quicker.

Once we finished writing our results, we unceremoniously dumped the cold water hot chocolate sludge down the kitchen sink. Ick.

What happened to the other two mugs? They were topped with a dollop of whipped cream and enjoyed!

Our hot chocolate science experiment and turned out great!

More STEAM Activities to Try
Hockey Science Christmas Science: Grow the Grinch's Heart Edible STEM Projects for Kids Marshmallow Engineering STEAM Building Challenge 28 Awesome STEM Challenges for the Elementary Classroom at Teach Junkie
STEM Activities for Kids in the Kitchen at iGame Mom

Do more science at home:

We love Green Kid Crafts boxes because they provide easy, ready-to-do STEM activities we can try at home. You'll receive easy-to-follow instructions plus the supplies that you need for up to 6 activities. You can get a monthly subscription or buy a single themed box. If you enjoyed our hot chocolate science experiment, you may enjoy the Kitchen Science or the monthly Discovery Box subscription.

Click here for the Kitchen Science box.

Click here for the monthly Discovery Box subscription.

Are you looking for more activities?

Join our fun Facebook community, Creative Family Fun for Busy Families, for daily activities that are great for kids and families. We'll chat, share, and have fun. It's a safe and private place to share idea for family and kids activities. I'd love for you to join me! Just click the link below, request to join, and answer the questions (they're easy, I promise). Come join the fun! Join the Creative Family Fun for Busy Families community here.

The following two tabs change content below.

# data[].attributes.attachment_link.description
This hot chocolate science experiment is a fun way to learn about how temperature affects the rate at which hot chocolate dissolves.

# data[].attributes.body
I thought both lessons were really cool and I would do both lessons. I had a hard time deciding which I liked because they were both hands on and fun. I love hot chocolate so I chose that one.
-Courtney Drennen

# data[].attributes.attachment_link.readable_text
I love my girls' natural curiosity when it comes to science. So, when my daughter asked me "Can we do a hot chocolate science experiment?" I knew it was time to get creative.

Working together, we came up with an amazing STEM activity.

When we make instant hot chocolate, we dissolve the contents of the packet into hot water. We decided to find out if temperature affected the speed that it dissolves.

Let's get started!

Disclosure: There are Amazon Affiliate and other affiliate links in this article which means, at no additional cost to you, we could receive compensation for our recommendations. You can read our full disclosure policy on our Disclosure Page for more details.

Supplies Needed for Your Hot Chocolate Science Project

First we needed to gather our supplies. Luckily most of the items were already in our kitchen.

Here's what you'll need:

Three heat-proof mugs
Three packets of instant hot chocolate
Measuring cup
Water
Spoons
Stopwatch or timer
Notebook for recording your results.

How to Do Your Hot Chocolate Science Experiment

We started our experiment by making a prediction. Which temperature of water would dissolve the hot chocolate the quickest?

The girls made their prediction (they chose hot) and then it was time to experiment.

We started by emptying our hot chocolate packets into our mugs, one packet per mug. Then we moved on to testing the different temperatures of water.

We tested each temperature, one at a time. We were very vague with our temperatures, using ice cold water, room temperature water, and hot water. You can always add a kitchen thermometer to measure the temperature of the water to add an extra measurement element to your experiment.

My girls took turns measuring the water, stirring, and operating the stopwatch. We used the digital stopwatch on my phone to time how long the hot chocolate took to dissolve.

For each cup, we measured 6 oz. of water. We used cold water from our refrigerator over ice, lukewarm water from the tap, and I did my grown-up duty and heated water in the microwave for the last mug.

Once the water was added to a mug, one girl started the stopwatch and the other started stirring. We stopped the stopwatch as soon as we saw the hot chocolate had dissolved.

Does Hot Chocolate Dissolve Faster in Hot Water or Cold Water?

We started with the ice cold water. My oldest daughter was in charge of the stirring. She stirred and stirred and stirred some more. It wouldn't dissolve. Eventually, we made the decision to stop after three minutes. You can see the results above. Disgusting!

We moved on to the room temperature water, which clocked in at 1 minute 38 seconds. And, then the hot water, which only took 28 seconds.

The results: hot water takes the least amount of time. We predicted that because the instructions said to use hot water when we made hot chocolate. (And, it's called hot chocolate after all...) But, now we know why we need to use hot water.

Why Does Hot Chocolate Powder Dissolve Faster in Hot Water?

Hot water has more energy than cold water. With more energy, the molecules in the water move faster breaking down the hot chocolate mix quicker.

Once we finished writing our results, we unceremoniously dumped the cold water hot chocolate sludge down the kitchen sink. Ick.

What happened to the other two mugs? They were topped with a dollop of whipped cream and enjoyed!

Our hot chocolate science experiment and turned out great!

More STEAM Activities to Try
Hockey Science Christmas Science: Grow the Grinch's Heart Edible STEM Projects for Kids Marshmallow Engineering STEAM Building Challenge 28 Awesome STEM Challenges for the Elementary Classroom at Teach Junkie
STEM Activities for Kids in the Kitchen at iGame Mom

Do more science at home:

We love Green Kid Crafts boxes because they provide easy, ready-to-do STEM activities we can try at home. You'll receive easy-to-follow instructions plus the supplies that you need for up to 6 activities. You can get a monthly subscription or buy a single themed box. If you enjoyed our hot chocolate science experiment, you may enjoy the Kitchen Science or the monthly Discovery Box subscription.

Click here for the Kitchen Science box.

Click here for the monthly Discovery Box subscription.

Are you looking for more activities?

Join our fun Facebook community, Creative Family Fun for Busy Families, for daily activities that are great for kids and families. We'll chat, share, and have fun. It's a safe and private place to share idea for family and kids activities. I'd love for you to join me! Just click the link below, request to join, and answer the questions (they're easy, I promise). Come join the fun! Join the Creative Family Fun for Busy Families community here.

The following two tabs change content below.

# data[].attributes.attachment_link.description
This hot chocolate science experiment is a fun way to learn about how temperature affects the rate at which hot chocolate dissolves.

# data[].attributes.body
I chose the photography scavenger hunt. My reason for choosing it was how active and flexible the lesson is, kids would be getting up and moving around along with being able to incorporate it in any lesson subject area or topic.
-Austin Miller

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I've wanted to do a photo scavenger hunt with the kids for a long, long time. I always love any kind of scavenger hunt. And the boys love taking photos.

But the boys don't have their own camera, and all I have is my DSLR that I use (affiliate link) and I don't want to hand that over to the boys (I'm nervous of it breaking... and I couldn't go without it until I got it replaced).

I finally realized that the iPad mini (affiliate link) that we have can be used! Duh! It took me forever to come up with this solution.

Even better, it let me put the photo scavenger hunt right on the iPad for the kids to search for and then have George take photos of what he found.

I decided to hunt around the yard to find different shapes of objects. A square, circle, triangle and rectangle.

Triangles were the hardest to find, but found them in spokes of the cars and bikes.

Squares I found in our porch railing and skirting.

Circles were everywhere! I found a bell on their bikes, the ends of hoses, wheels of the million toys we have.

I took about a dozen photos of shapes I found around the yard and stored them in an album on the iPad for George.

George then took the iPad around the yard to find those shapes.

Once he found it, he switched over to the camera app to snap a photo of it too.

I have a collection of both my photos and his photos and its fun to compare the two!

Below is my photo for the triangle (I didn't have the red triangle and text in the photos, I just added that for this post to be clear).

And below is the photo that George took of the triangles he found.

He got the shape and object in every photo. But definitely not the same photo!

Below is my rectangle photo of a brick on the side of our house.

And below is George's version of the rectangle.

He didn't crop up nearly as close (maybe because I've told him time and time again to stay out of my plant beds and he's finally learning to listen).

This is the photo I took of the circle, a bell on his bike.

George tried to get it just the same! He did awesome hunting for them and finding the shapes!

This is his photo of the circle bell.

This photo scavenger hunt for the kids wasn't nearly as daunting as I thought it would be to put together. It took all of five minutes for me to walk around and find the shapes and snap the photos.

George loves anything to do with technology, so using the iPad to go on the scavenger hunt was a winner. Plus he got to take photos which he loves to do with it.

Got a hunter? The kids will love to go on any of these 32 ideas for scavenger hunts!

And in the meantime, he practiced his shapes. Triangles are still tough for him, but he's got squares and rectangles down now!

More move and learn ideas:

# data[].attributes.attachment_link.title
Photo Scavenger Hunt for Kids to Find Shapes

# data[].attributes.attachment_link.description
I've wanted to do a photo scavenger hunt with the kids for a long, long time. I always love any kind of scavenger hunt. And the boys love taking photos. But the boys don't have their own camera, and all I have is my DSLR that I use (affiliate link) and I don't want to hand that over to the boys (I'm nervous of it breaking...

# data[].attributes.headline
I love this lesson because it is kinesthetic, and allows students to move around the classroom. Also, students take pictures throughout to capture their evidence. This keeps the students engaged throughout the entire lesson.

# data[].attributes.subject
I love this lesson because it is kinesthetic, and allows students to move around the classroom. Also, students take pictures throughout to capture their evidence. This keeps the students engaged throughout the entire lesson.

# data[].attributes.body
-Jackie Flick

# data[].attributes.attachment_link.readable_text
I've wanted to do a photo scavenger hunt with the kids for a long, long time. I always love any kind of scavenger hunt. And the boys love taking photos.

But the boys don't have their own camera, and all I have is my DSLR that I use (affiliate link) and I don't want to hand that over to the boys (I'm nervous of it breaking... and I couldn't go without it until I got it replaced).

I finally realized that the iPad mini (affiliate link) that we have can be used! Duh! It took me forever to come up with this solution.

Even better, it let me put the photo scavenger hunt right on the iPad for the kids to search for and then have George take photos of what he found.

I decided to hunt around the yard to find different shapes of objects. A square, circle, triangle and rectangle.

Triangles were the hardest to find, but found them in spokes of the cars and bikes.

Squares I found in our porch railing and skirting.

Circles were everywhere! I found a bell on their bikes, the ends of hoses, wheels of the million toys we have.

I took about a dozen photos of shapes I found around the yard and stored them in an album on the iPad for George.

George then took the iPad around the yard to find those shapes.

Once he found it, he switched over to the camera app to snap a photo of it too.

I have a collection of both my photos and his photos and its fun to compare the two!

Below is my photo for the triangle (I didn't have the red triangle and text in the photos, I just added that for this post to be clear).

And below is the photo that George took of the triangles he found.

He got the shape and object in every photo. But definitely not the same photo!

Below is my rectangle photo of a brick on the side of our house.

And below is George's version of the rectangle.

He didn't crop up nearly as close (maybe because I've told him time and time again to stay out of my plant beds and he's finally learning to listen).

This is the photo I took of the circle, a bell on his bike.

George tried to get it just the same! He did awesome hunting for them and finding the shapes!

This is his photo of the circle bell.

This photo scavenger hunt for the kids wasn't nearly as daunting as I thought it would be to put together. It took all of five minutes for me to walk around and find the shapes and snap the photos.

George loves anything to do with technology, so using the iPad to go on the scavenger hunt was a winner. Plus he got to take photos which he loves to do with it.

Got a hunter? The kids will love to go on any of these 32 ideas for scavenger hunts!

And in the meantime, he practiced his shapes. Triangles are still tough for him, but he's got squares and rectangles down now!

More move and learn ideas:

# data[].attributes.attachment_link.title
Photo Scavenger Hunt for Kids to Find Shapes

# data[].attributes.attachment_link.description
I've wanted to do a photo scavenger hunt with the kids for a long, long time. I always love any kind of scavenger hunt. And the boys love taking photos. But the boys don't have their own camera, and all I have is my DSLR that I use (affiliate link) and I don't want to hand that over to the boys (I'm nervous of it breaking...

# data[].attributes.body
I really like this lesson because it allows the kids to connect math to the real world, and I feel that that is a question a lot of kids always ask. "when will we ever use this in the real world".

# data[].attributes.attachment_link.readable_text
I've wanted to do a photo scavenger hunt with the kids for a long, long time. I always love any kind of scavenger hunt. And the boys love taking photos.

But the boys don't have their own camera, and all I have is my DSLR that I use (affiliate link) and I don't want to hand that over to the boys (I'm nervous of it breaking... and I couldn't go without it until I got it replaced).

I finally realized that the iPad mini (affiliate link) that we have can be used! Duh! It took me forever to come up with this solution.

Even better, it let me put the photo scavenger hunt right on the iPad for the kids to search for and then have George take photos of what he found.

I decided to hunt around the yard to find different shapes of objects. A square, circle, triangle and rectangle.

Triangles were the hardest to find, but found them in spokes of the cars and bikes.

Squares I found in our porch railing and skirting.

Circles were everywhere! I found a bell on their bikes, the ends of hoses, wheels of the million toys we have.

I took about a dozen photos of shapes I found around the yard and stored them in an album on the iPad for George.

George then took the iPad around the yard to find those shapes.

Once he found it, he switched over to the camera app to snap a photo of it too.

I have a collection of both my photos and his photos and its fun to compare the two!

Below is my photo for the triangle (I didn't have the red triangle and text in the photos, I just added that for this post to be clear).

And below is the photo that George took of the triangles he found.

He got the shape and object in every photo. But definitely not the same photo!

Below is my rectangle photo of a brick on the side of our house.

And below is George's version of the rectangle.

He didn't crop up nearly as close (maybe because I've told him time and time again to stay out of my plant beds and he's finally learning to listen).

This is the photo I took of the circle, a bell on his bike.

George tried to get it just the same! He did awesome hunting for them and finding the shapes!

This is his photo of the circle bell.

This photo scavenger hunt for the kids wasn't nearly as daunting as I thought it would be to put together. It took all of five minutes for me to walk around and find the shapes and snap the photos.

George loves anything to do with technology, so using the iPad to go on the scavenger hunt was a winner. Plus he got to take photos which he loves to do with it.

Got a hunter? The kids will love to go on any of these 32 ideas for scavenger hunts!

And in the meantime, he practiced his shapes. Triangles are still tough for him, but he's got squares and rectangles down now!

More move and learn ideas:

# data[].attributes.attachment_link.title
Photo Scavenger Hunt for Kids to Find Shapes

# data[].attributes.attachment_link.description
I've wanted to do a photo scavenger hunt with the kids for a long, long time. I always love any kind of scavenger hunt. And the boys love taking photos. But the boys don't have their own camera, and all I have is my DSLR that I use (affiliate link) and I don't want to hand that over to the boys (I'm nervous of it breaking...

# data[].attributes.body
This activity is so great because it gets student up and moving when they have been sitting all day. This is also nice because students could show each other their shapes and see what other students found.
-Victoria Malpica

# data[].attributes.attachment_link.readable_text
I've wanted to do a photo scavenger hunt with the kids for a long, long time. I always love any kind of scavenger hunt. And the boys love taking photos.

But the boys don't have their own camera, and all I have is my DSLR that I use (affiliate link) and I don't want to hand that over to the boys (I'm nervous of it breaking... and I couldn't go without it until I got it replaced).

I finally realized that the iPad mini (affiliate link) that we have can be used! Duh! It took me forever to come up with this solution.

Even better, it let me put the photo scavenger hunt right on the iPad for the kids to search for and then have George take photos of what he found.

I decided to hunt around the yard to find different shapes of objects. A square, circle, triangle and rectangle.

Triangles were the hardest to find, but found them in spokes of the cars and bikes.

Squares I found in our porch railing and skirting.

Circles were everywhere! I found a bell on their bikes, the ends of hoses, wheels of the million toys we have.

I took about a dozen photos of shapes I found around the yard and stored them in an album on the iPad for George.

George then took the iPad around the yard to find those shapes.

Once he found it, he switched over to the camera app to snap a photo of it too.

I have a collection of both my photos and his photos and its fun to compare the two!

Below is my photo for the triangle (I didn't have the red triangle and text in the photos, I just added that for this post to be clear).

And below is the photo that George took of the triangles he found.

He got the shape and object in every photo. But definitely not the same photo!

Below is my rectangle photo of a brick on the side of our house.

And below is George's version of the rectangle.

He didn't crop up nearly as close (maybe because I've told him time and time again to stay out of my plant beds and he's finally learning to listen).

This is the photo I took of the circle, a bell on his bike.

George tried to get it just the same! He did awesome hunting for them and finding the shapes!

This is his photo of the circle bell.

This photo scavenger hunt for the kids wasn't nearly as daunting as I thought it would be to put together. It took all of five minutes for me to walk around and find the shapes and snap the photos.

George loves anything to do with technology, so using the iPad to go on the scavenger hunt was a winner. Plus he got to take photos which he loves to do with it.

Got a hunter? The kids will love to go on any of these 32 ideas for scavenger hunts!

And in the meantime, he practiced his shapes. Triangles are still tough for him, but he's got squares and rectangles down now!

More move and learn ideas:

# data[].attributes.attachment_link.title
Photo Scavenger Hunt for Kids to Find Shapes

# data[].attributes.attachment_link.description
I've wanted to do a photo scavenger hunt with the kids for a long, long time. I always love any kind of scavenger hunt. And the boys love taking photos. But the boys don't have their own camera, and all I have is my DSLR that I use (affiliate link) and I don't want to hand that over to the boys (I'm nervous of it breaking...

# data[].attributes.body
I chose this lesson because I think you could make this so much fun for all ages. It such a fun way to engage kids.
-Courtney Drennen

# data[].attributes.attachment_link.readable_text
I've wanted to do a photo scavenger hunt with the kids for a long, long time. I always love any kind of scavenger hunt. And the boys love taking photos.

But the boys don't have their own camera, and all I have is my DSLR that I use (affiliate link) and I don't want to hand that over to the boys (I'm nervous of it breaking... and I couldn't go without it until I got it replaced).

I finally realized that the iPad mini (affiliate link) that we have can be used! Duh! It took me forever to come up with this solution.

Even better, it let me put the photo scavenger hunt right on the iPad for the kids to search for and then have George take photos of what he found.

I decided to hunt around the yard to find different shapes of objects. A square, circle, triangle and rectangle.

Triangles were the hardest to find, but found them in spokes of the cars and bikes.

Squares I found in our porch railing and skirting.

Circles were everywhere! I found a bell on their bikes, the ends of hoses, wheels of the million toys we have.

I took about a dozen photos of shapes I found around the yard and stored them in an album on the iPad for George.

George then took the iPad around the yard to find those shapes.

Once he found it, he switched over to the camera app to snap a photo of it too.

I have a collection of both my photos and his photos and its fun to compare the two!

Below is my photo for the triangle (I didn't have the red triangle and text in the photos, I just added that for this post to be clear).

And below is the photo that George took of the triangles he found.

He got the shape and object in every photo. But definitely not the same photo!

Below is my rectangle photo of a brick on the side of our house.

And below is George's version of the rectangle.

He didn't crop up nearly as close (maybe because I've told him time and time again to stay out of my plant beds and he's finally learning to listen).

This is the photo I took of the circle, a bell on his bike.

George tried to get it just the same! He did awesome hunting for them and finding the shapes!

This is his photo of the circle bell.

This photo scavenger hunt for the kids wasn't nearly as daunting as I thought it would be to put together. It took all of five minutes for me to walk around and find the shapes and snap the photos.

George loves anything to do with technology, so using the iPad to go on the scavenger hunt was a winner. Plus he got to take photos which he loves to do with it.

Got a hunter? The kids will love to go on any of these 32 ideas for scavenger hunts!

And in the meantime, he practiced his shapes. Triangles are still tough for him, but he's got squares and rectangles down now!

More move and learn ideas:

# data[].attributes.attachment_link.title
Photo Scavenger Hunt for Kids to Find Shapes

# data[].attributes.attachment_link.description
I've wanted to do a photo scavenger hunt with the kids for a long, long time. I always love any kind of scavenger hunt. And the boys love taking photos. But the boys don't have their own camera, and all I have is my DSLR that I use (affiliate link) and I don't want to hand that over to the boys (I'm nervous of it breaking...

# data[].attributes.body
I chose this lesson because I like how students learn about animals and their traits through technology! I think that it is super cool to use technology to learn about habitat and different traits animals have.
-Alexis Cancila

# data[].attributes.attachment_link.title
Creature Powers: Lesson Plan | PBS KIDS ScratchJr | PBS LearningMedia

# data[].attributes.attachment_link.description
Animate animal traits with the WILD KRATTS!

# data[].attributes.headline
In this lesson students use an LED light bulb to learn how a battery works in a simply circuit. I remember doing this exact activity as a kid and I loved. It allows students to visually see that energy can travel through a variety of objects.

# data[].attributes.subject
In this lesson students use an LED light bulb to learn how a battery works in a simply circuit. I remember doing this exact activity as a kid and I loved. It allows students to visually see that energy can travel through a variety of objects.

# data[].attributes.body
-Jackie Flick

# data[].attributes.attachment_link.readable_text
Quick Look

Grade Level: 4 (3-5)

Time Required: 45 minutes

Expendable Cost/Group: US $2.00

Group Size: 3

Activity Dependency: None

Subject Areas: Physical Science, Science and Technology

NGSS Performance Expectations:

Summary Students use potatoes to light an LED clock (or light bulb) as they learn how a battery works in a simple circuit and how chemical energy changes to electrical energy. As they learn more about electrical energy, they better understand the concepts of voltage, current and resistance.
This engineering curriculum aligns to Next Generation Science Standards (NGSS).

Engineering Connection

Engineers use batteries to store energy in a wide range of situations. A solid electrolyte battery is most suitable in very extreme weather conditions, while nickel-zinc batteries work best in electric vehicles. Energy engineers continually evolve technology to improve the performance and life-cycle costs of batteries that store solar and wind energy. When designing a battery, engineers keep in mind the needs of the application, and use different substances to create current flow. They consider characteristics such as power output, ability to recharge, reliability, size, safety, heat generation, length of life cycle, abuse tolerance, cost and ability to be recycled. Isn't the power of engineering creativity amazing?

Learning Objectives

After this activity, students should be able to:

Describe the flow of electrical energy through a simple circuit.

Explain why a light bulb may take more than one battery to light up.

Explain the role of electrical engineers in the development of electricity sources and the products that use electricity.

Educational Standards

Each TeachEngineering lesson or activity is correlated to one or more K-12 science, technology, engineering or math (STEM) educational standards.

All 100,000+ K-12 STEM standards covered in TeachEngineering are collected, maintained and packaged by the Achievement Standards Network (ASN), a project of D2L (www.achievementstandards.org).

In the ASN, standards are hierarchically structured: first by source; e.g., by state; within source by type; e.g., science or mathematics; within type by subtype, then by grade, etc.

NGSS Performance Expectation

Click to view other curriculum aligned to this Performance Expectation

This activity focuses on the following Three Dimensional Learning aspects of NGSS:

Science & Engineering Practices

Disciplinary Core Ideas

Crosscutting Concepts

Make observations to produce data to serve as the basis for evidence for an explanation of a phenomenon or test a design solution.

Energy can be moved from place to place by moving objects or through sound, light, or electric currents. Energy is present whenever there are moving objects, sound, light, or heat. When objects collide, energy can be transferred from one object to another, thereby changing their motion. In such collisions, some energy is typically also transferred to the surrounding air; as a result, the air gets heated and sound is produced. Light also transfers energy from place to place. Energy can also be transferred from place to place by electric currents, which can then be used locally to produce motion, sound, heat, or light. The currents may have been produced to begin with by transforming the energy of motion into electrical energy.

Energy can be transferred in various ways and between objects.

Suggest an alignment not listed above

Materials List

To make a potato battery, each group needs:

3 copper pennies (or copper strips), one per potato

3 zinc nails; these are galvanized nails, available at hardware stores

5 insulated wires, 15-20 cm (6-8 inches) long, with alligator clips at the ends

1 low-current, light emitting diode (LED) clock (or LCD clock) requiring ~1.5 volts (or a small LED)

OR above materials can be purchased cumulatively in a kit, available online

For the entire class to share or one per team:

(optional) multimeter(s) or voltmeter(s); a multimeter measures current, voltage and resistance of a circuit; available at Radio Shack or other electronics stores or websites

Worksheets and Attachments
Visit [www.teachengineering.org/activities/view/cub_energy2_lesson04_activity2] to print or download.

Introduction/Motivation

What is electrical energy? From where does it come? Can you think of anything that needs electrical energy to work? How about lamps, music players, TVs and ovens? How do we get the power to run these devices? What role do electrical engineers play in improving our lives?

One place we can find electrical energy in our homes is at a wall outlet. So, how does electrical energy reach the wall outlet in our house? The energy comes from an electrical power plant, which usually makes electrical energy from burning fossil fuels, such as coal and oil. The heat energy from the burning fuel heats up water. When the water boils, it becomes steam, which flows through a pipe into a turbine (a wheel with blades). As the turbine spins from the steam, it turns a generator (a spinning magnet) that unbalances the charges in nearby atoms and produces a current of electricity. The electrical current flows through protected wires to our house.

How else can we power electrical appliances? That's right, from a battery. A battery works by providing electrons with a solution in which they can move around. Have you ever noticed that some batteries have a copper end that is positive (shown with a plus [+] sign) and another end that is negative (shown with a minus [-] sign)? Zinc is a metal that likes to give its electrons to copper. Usually, zinc just gives its electrons to copper and then the process stops. However, if you provide the electrons with a solution (called an electrolyte) to help them move to the copper, and you give the electrons a wire in which they can move from the copper back to the zinc, you can produce a circuit and a flowing path of electrical energy. (Note: Conventional current flows from positive to negative, so from the copper, through the wire, back to the zinc. The electrons actually flow negative to positive.)

A circuit is a complete path of electrical energy. This means that electrical energy or charge is produced or stored somewhere ( voltage) and has a path for the charge to flow (or current). Another part of a circuit is a resistance, such as a light bulb. Electrical engineers create circuits to help electrical energy perform work, such as lighting a room or keeping food cold. An appliance, light bulb or almost any device that uses electrical energy is a resistance. A resistance prevents or slows an electrical current or charge from moving. When electrical current flows through a source of resistance, it can be changed into light or heat or sound. Even though you cannot see it, the light bulb or appliance slows down the electrical charge.

Electrical engineers help develop the many modern products and appliances that require electrical energy. Electrical engineers also help create the technology used to generate the electrical energy in power plants in the first place. These engineers know a lot about circuits and they continually work to find better ways to store electrical charge and generate electrical current without using nonrenewable fossil fuels such as coal and oil. These electrical engineers are very important in almost everything we do! Essentially, electrical engineers create improvements for society and help save our planet for future generations. Today, we are going to be electrical engineers and learn more about how electrical energy works in a circuit. We are also going to look at generating electrical current from the energy stored in a potato! Do you think we can light a bulb with a potato? Let's try it!

Procedure

Background

How does a potato battery work? The copper (Cu) atoms attract electrons more than the zinc (Zn) atoms. If you place a strip of copper and a strip of zinc in contact with each other, many electrons pass from the zinc to the copper. As they concentrate on the copper, the electrons repel each other. When the force of repulsion between electrons and the force of attraction of electrons to the copper become equalized, the flow of electrons stops. Unfortunately it is not possible to take advantage of this behavior to produce electricity because the flow of charges stops almost immediately. On the other hand, if you bathe the two strips in a conductive solution, and connect them externally with a wire, the reactions between the electrodes and the solution continually furnish the circuit with charges. In this way, the process that produces the electrical energy continues and becomes useful. In a conductive solution, the charge is carried by ions that move through the solution. In the solid state, the ions are not able to move around freely. However, once they are dissolved in water, they become completely mobile. They can "swim" around in the water and thus can respond to an electric current from a battery. That current supplies electrons that cause positive ions to flow in one direction and negative ions to flow in the opposite direction. The ions carry electrical charge from one electrode to another, completing the electrical circuit.

For a conductive solution, use any electrolyte, whether it is an acid, base or salt solution. An electrolyte is a substance whose aqueous solution contains various ions and thus conducts electricity. Therefore, the more free ions a solution has, the better conductor it will be. Many fruits and vegetables contain juices rich in ions and are therefore good electrical conductors.

Like any battery, a potato battery has a limited life span. The electrodes undergo chemical reactions that block the flow of electricity. The electromotive force diminishes and the battery stops working. Usually, what happens is the production of hydrogen at the copper electrode and the zinc electrode acquires deposits of oxides that act as a barrier between the metal and the electrolyte. This is referred to as the electrodes being polarized. To achieve a longer life and higher voltages and current flows, it is necessary to use electrolytes better suited for the purpose. Commercial batteries, apart from their normal electrolyte, contain chemicals with an affinity for hydrogen, which combine with the hydrogen before it can polarize the electrodes.

Before the Activity

With the Students

1. Divide the class into teams of two or three students each. Hand out the materials.

2. Direct groups to carefully place the zinc nails and copper pennies into the potato. Make sure the two different metals do not touch each other in the potato (see Figure 1).

3. Connect one alligator clip to the end of the penny sticking out of the potato and another alligator clip to the end of the nail sticking out of the potato (see Figure 1).

Figure 1. Placement of the nail, penny and alligator clips.

1. (If you have a multimeter) Tell students that a multimeter is an instrument that measures current, voltage and resistance of a circuit, and is a tool (created by and) often used by engineers. Set the multimeter on a low "DC volts" scale for voltage and "DC milliamps" for current, so students can see the charge that one potato can produce. Expect the potato to produce just less than 1 volt. Encourage students to convert the decimal readout from the multimeter to a fraction (for example, 0.82 volts = 82/100 volts).

2. Have the students figure out how many potatoes they need to light their LED clock (or clock). For example, if their potato produces a voltage of 0.8 volts, then they may need two potatoes to power a 1.5 voltage LED.

3. Have students experiment to figure out how to connect two potatoes together. To connect two potatoes in series (to add more voltage), place a penny and nail into a second potato, and connect the wire from the zinc nail in the first potato to the copper penny in the second. Then, add a third wire to the zinc nail in the second potato. Always remember to connect the copper (positive) end of the potato (battery) to the zinc (negative) end of the next potato (see Figure 2).

Figure 2. Activity setup to create a potato battery to power an LED clock.

1. Expect two potatoes in series to be able to light an LED; however, you might need three. Show students how to connect the LEDs to the potato in the correct manner, that is, the positive end of the LED to the negative end of the potato battery (zinc nail) and the negative end of the LED to the positive end of the potato battery (copper penny).

2. Have students discuss how the potatoes provide the electrolyte (solution) for the chemical battery to work. Ask for suggestions of other foods we could try (for example, lemons, berries, apples).

3. Ask students to complete the worksheet either individually or in pairs. After they finish, have them compare answers with a peer or another pair, giving all students time to finish.

Vocabulary/Definitions

conductor: An object that allows the transfer of electrons.

current: The movement of electrons.

electrical energy: Energy produced through the movement of electrons (voltage X current).

electrolyte: A solution that conducts electricity.

energy: The ability to do work.

insulator: An object that inhibits the transfer of electrons.

resistance: Objects or substances that prevent the passage of a steady electric current.

voltage: The amount of energy produced.

Assessment

Pre-Activity Assessment

Brainstorming: In small groups, have students engage in open discussion. Remind them that no idea or suggestion is "silly." All ideas should be respectfully heard. Take an uncritical position, encourage wild ideas and discourage criticism of ideas. Ask students how many items they can think of that run on batteries. As a class, record their ideas on the board.

Quick Poll: Before the activity begins, ask the class a question and tally their responses on the board. Ask: Can we get electrical energy from a fruit or vegetable?

Activity Embedded Assessment

Worksheet /Pairs Check: Have students work individually or in pairs on the Make a Battery Worksheet. After they finish, have them compare answers with a peer or another pair, giving all students time to finish the worksheet.

Hypothesize: Ask each group what would happen if we added more potatoes in a row to our circuits? (Answer: Adding more potatoes in a row is the same as adding batteries in a row. The voltage of each piece of potato is added up. Thus, the voltage of our circuit would increase. On the other hand, the current of our circuit would not increase. Current is not dependent on how many potatoes but is related to the size of each potato individually.)

Post-Activity Assessment

Problem Solving: Present the class with the following math problems and ask students to calculate how many of each vegetable or fruit are needed to light the bulb.

If a lemon produces 1 Volt of energy, how many lemons would you need to light a 2 Volt light bulb? (Answer: 2)

If a potato produces 0.8 Volts of energy, how many potatoes would you need to light a 1.5 Volt light bulb? (Answer: 2)

If a potato produces 0.8 Volts of energy, how many potatoes would you need to light a 3 Volt digital clock? (Answer: 4)

If you have a lemon that produces 1 Volt of energy and an apple that produces 1 Volt of energy, can you light a 3 Volt clock? (Answer: No, you would need one more lemon or apple.)

Diagramming: Engineers must understand how circuits work in order to develop cool new technologies. Draw a picture of your potato battery. Label the battery (voltage) and the resistance (light bulb). Draw an arrow to show the current flow (from the copper end to the zinc end). List two cool products that an engineer could develop that run off a fruit battery.

Troubleshooting Tips

If the LED clock, light or small light bulbs do not work, check the setup of the potato battery. Perhaps the ends are not all connected from negative to positive, or perhaps there is not enough potato voltage. Check the voltage of the potato using a multimeter or voltmeter. Another possibility is having enough voltage, but not enough current to light the bulb, which is why it is recommended to use only very low-volt LED clocks or bulbs. Also, try using more potatoes (i.e., 5 potato halves) to strengthen conductivity. Try different LED colors (for example, the blue LED may work better than the red).

Lemons and oranges also work well for this activity. They work best if you first roll them on a table top, which breaks down the cells inside so more juice flows through the fruit (current).

Some people have more conduction success using copper strips instead of copper pennies (can also wrap the pennies in copper ribbon).

Soaking the potatoes in Gatorade overnight can make them more conductive.

Activity Extensions

At activity end, before students disassemble their potato batteries, it is fun to have the entire class connect their fruit batteries in series, making "a serious tater circle."

Have students try the activity again using different fruits or vegetables! Many fruits and vegetables work, such as lemons, limes, apples and carrots. Have students compare and contrast the performance of different fruits and vegetables.

Have students complete the activity again using an electrolyte solution, such as salt water or vinegar. Have them compare and contrast the performance of different electrolyte solutions.

To add a math component, have students use the multimeter to compare the flow of electricity for several different fruits as well as to the total amount of fruits used. Ask them to graph the results and hypothesize what is happening.

Activity Scaling

Have more advanced students experiment with parallel and series configurations using different numbers of potatoes.

References

Dictionary.com. Lexico Publishing Group, LLC. Accessed September 28, 2005. (Source of some vocabulary definitions, with some adaptation) http://www.dictionary.com

Phillips, W.D. Chapter 2P: Using a Multimeter. Design Electronics (online textbook) DOCTRONICS Educational Publishing, UK. Accessed September 28, 2005. (Good design, technology and electronics resources.) http://www.doctronics.co.uk/meter.htm

Copyright © 2005 by Regents of the University of Colorado

Contributors Sharon D. Perez-Suarez; Jeff Lyng; Malinda Schaefer Zarske; Denise W. Carlson; Janet Yowell

Supporting Program Integrated Teaching and Learning Program, College of Engineering, University of Colorado Boulder

Acknowledgements

The contents of this digital library curriculum were developed under grants from the Fund for the Improvement of Postsecondary Education (FIPSE), U.S. Department of Education, and the National Science Foundation (GK-12 grant no. 0338326). However, these contents do not necessarily represent the policies of the Department of Education or National Science Foundation, and you should not assume endorsement by the federal government.

Last modified: July 9, 2020

# data[].attributes.attachment_link.description
Students use potatoes to light an LED clock (or light bulb) as they learn how a battery works in a simple circuit and how chemical energy changes to electrical energy. As they learn more about electrical energy, they better understand the concepts of voltage, current and resistance.

# data[].attributes.body
I really love this activity because students watch as energy goes through something that they have seen and eaten before. I think that when students write their hypothesis, they could have a really fun time trying to figure out if electricity can really go through a potato! -Victoria Malpica

# data[].attributes.attachment_link.readable_text
Quick Look

Grade Level: 4 (3-5)

Time Required: 45 minutes

Expendable Cost/Group: US $2.00

Group Size: 3

Activity Dependency: None

Subject Areas: Physical Science, Science and Technology

NGSS Performance Expectations:

Summary Students use potatoes to light an LED clock (or light bulb) as they learn how a battery works in a simple circuit and how chemical energy changes to electrical energy. As they learn more about electrical energy, they better understand the concepts of voltage, current and resistance.
This engineering curriculum aligns to Next Generation Science Standards (NGSS).

Engineering Connection

Engineers use batteries to store energy in a wide range of situations. A solid electrolyte battery is most suitable in very extreme weather conditions, while nickel-zinc batteries work best in electric vehicles. Energy engineers continually evolve technology to improve the performance and life-cycle costs of batteries that store solar and wind energy. When designing a battery, engineers keep in mind the needs of the application, and use different substances to create current flow. They consider characteristics such as power output, ability to recharge, reliability, size, safety, heat generation, length of life cycle, abuse tolerance, cost and ability to be recycled. Isn't the power of engineering creativity amazing?

Learning Objectives

After this activity, students should be able to:

Describe the flow of electrical energy through a simple circuit.

Explain why a light bulb may take more than one battery to light up.

Explain the role of electrical engineers in the development of electricity sources and the products that use electricity.

Educational Standards

Each TeachEngineering lesson or activity is correlated to one or more K-12 science, technology, engineering or math (STEM) educational standards.

All 100,000+ K-12 STEM standards covered in TeachEngineering are collected, maintained and packaged by the Achievement Standards Network (ASN), a project of D2L (www.achievementstandards.org).

In the ASN, standards are hierarchically structured: first by source; e.g., by state; within source by type; e.g., science or mathematics; within type by subtype, then by grade, etc.

NGSS Performance Expectation

Click to view other curriculum aligned to this Performance Expectation

This activity focuses on the following Three Dimensional Learning aspects of NGSS:

Science & Engineering Practices

Disciplinary Core Ideas

Crosscutting Concepts

Make observations to produce data to serve as the basis for evidence for an explanation of a phenomenon or test a design solution.

Energy can be moved from place to place by moving objects or through sound, light, or electric currents. Energy is present whenever there are moving objects, sound, light, or heat. When objects collide, energy can be transferred from one object to another, thereby changing their motion. In such collisions, some energy is typically also transferred to the surrounding air; as a result, the air gets heated and sound is produced. Light also transfers energy from place to place. Energy can also be transferred from place to place by electric currents, which can then be used locally to produce motion, sound, heat, or light. The currents may have been produced to begin with by transforming the energy of motion into electrical energy.

Energy can be transferred in various ways and between objects.

Suggest an alignment not listed above

Materials List

To make a potato battery, each group needs:

3 copper pennies (or copper strips), one per potato

3 zinc nails; these are galvanized nails, available at hardware stores

5 insulated wires, 15-20 cm (6-8 inches) long, with alligator clips at the ends

1 low-current, light emitting diode (LED) clock (or LCD clock) requiring ~1.5 volts (or a small LED)

OR above materials can be purchased cumulatively in a kit, available online

For the entire class to share or one per team:

(optional) multimeter(s) or voltmeter(s); a multimeter measures current, voltage and resistance of a circuit; available at Radio Shack or other electronics stores or websites

Worksheets and Attachments
Visit [www.teachengineering.org/activities/view/cub_energy2_lesson04_activity2] to print or download.

Introduction/Motivation

What is electrical energy? From where does it come? Can you think of anything that needs electrical energy to work? How about lamps, music players, TVs and ovens? How do we get the power to run these devices? What role do electrical engineers play in improving our lives?

One place we can find electrical energy in our homes is at a wall outlet. So, how does electrical energy reach the wall outlet in our house? The energy comes from an electrical power plant, which usually makes electrical energy from burning fossil fuels, such as coal and oil. The heat energy from the burning fuel heats up water. When the water boils, it becomes steam, which flows through a pipe into a turbine (a wheel with blades). As the turbine spins from the steam, it turns a generator (a spinning magnet) that unbalances the charges in nearby atoms and produces a current of electricity. The electrical current flows through protected wires to our house.

How else can we power electrical appliances? That's right, from a battery. A battery works by providing electrons with a solution in which they can move around. Have you ever noticed that some batteries have a copper end that is positive (shown with a plus [+] sign) and another end that is negative (shown with a minus [-] sign)? Zinc is a metal that likes to give its electrons to copper. Usually, zinc just gives its electrons to copper and then the process stops. However, if you provide the electrons with a solution (called an electrolyte) to help them move to the copper, and you give the electrons a wire in which they can move from the copper back to the zinc, you can produce a circuit and a flowing path of electrical energy. (Note: Conventional current flows from positive to negative, so from the copper, through the wire, back to the zinc. The electrons actually flow negative to positive.)

A circuit is a complete path of electrical energy. This means that electrical energy or charge is produced or stored somewhere ( voltage) and has a path for the charge to flow (or current). Another part of a circuit is a resistance, such as a light bulb. Electrical engineers create circuits to help electrical energy perform work, such as lighting a room or keeping food cold. An appliance, light bulb or almost any device that uses electrical energy is a resistance. A resistance prevents or slows an electrical current or charge from moving. When electrical current flows through a source of resistance, it can be changed into light or heat or sound. Even though you cannot see it, the light bulb or appliance slows down the electrical charge.

Electrical engineers help develop the many modern products and appliances that require electrical energy. Electrical engineers also help create the technology used to generate the electrical energy in power plants in the first place. These engineers know a lot about circuits and they continually work to find better ways to store electrical charge and generate electrical current without using nonrenewable fossil fuels such as coal and oil. These electrical engineers are very important in almost everything we do! Essentially, electrical engineers create improvements for society and help save our planet for future generations. Today, we are going to be electrical engineers and learn more about how electrical energy works in a circuit. We are also going to look at generating electrical current from the energy stored in a potato! Do you think we can light a bulb with a potato? Let's try it!

Procedure

Background

How does a potato battery work? The copper (Cu) atoms attract electrons more than the zinc (Zn) atoms. If you place a strip of copper and a strip of zinc in contact with each other, many electrons pass from the zinc to the copper. As they concentrate on the copper, the electrons repel each other. When the force of repulsion between electrons and the force of attraction of electrons to the copper become equalized, the flow of electrons stops. Unfortunately it is not possible to take advantage of this behavior to produce electricity because the flow of charges stops almost immediately. On the other hand, if you bathe the two strips in a conductive solution, and connect them externally with a wire, the reactions between the electrodes and the solution continually furnish the circuit with charges. In this way, the process that produces the electrical energy continues and becomes useful. In a conductive solution, the charge is carried by ions that move through the solution. In the solid state, the ions are not able to move around freely. However, once they are dissolved in water, they become completely mobile. They can "swim" around in the water and thus can respond to an electric current from a battery. That current supplies electrons that cause positive ions to flow in one direction and negative ions to flow in the opposite direction. The ions carry electrical charge from one electrode to another, completing the electrical circuit.

For a conductive solution, use any electrolyte, whether it is an acid, base or salt solution. An electrolyte is a substance whose aqueous solution contains various ions and thus conducts electricity. Therefore, the more free ions a solution has, the better conductor it will be. Many fruits and vegetables contain juices rich in ions and are therefore good electrical conductors.

Like any battery, a potato battery has a limited life span. The electrodes undergo chemical reactions that block the flow of electricity. The electromotive force diminishes and the battery stops working. Usually, what happens is the production of hydrogen at the copper electrode and the zinc electrode acquires deposits of oxides that act as a barrier between the metal and the electrolyte. This is referred to as the electrodes being polarized. To achieve a longer life and higher voltages and current flows, it is necessary to use electrolytes better suited for the purpose. Commercial batteries, apart from their normal electrolyte, contain chemicals with an affinity for hydrogen, which combine with the hydrogen before it can polarize the electrodes.

Before the Activity

With the Students

1. Divide the class into teams of two or three students each. Hand out the materials.

2. Direct groups to carefully place the zinc nails and copper pennies into the potato. Make sure the two different metals do not touch each other in the potato (see Figure 1).

3. Connect one alligator clip to the end of the penny sticking out of the potato and another alligator clip to the end of the nail sticking out of the potato (see Figure 1).

Figure 1. Placement of the nail, penny and alligator clips.

1. (If you have a multimeter) Tell students that a multimeter is an instrument that measures current, voltage and resistance of a circuit, and is a tool (created by and) often used by engineers. Set the multimeter on a low "DC volts" scale for voltage and "DC milliamps" for current, so students can see the charge that one potato can produce. Expect the potato to produce just less than 1 volt. Encourage students to convert the decimal readout from the multimeter to a fraction (for example, 0.82 volts = 82/100 volts).

2. Have the students figure out how many potatoes they need to light their LED clock (or clock). For example, if their potato produces a voltage of 0.8 volts, then they may need two potatoes to power a 1.5 voltage LED.

3. Have students experiment to figure out how to connect two potatoes together. To connect two potatoes in series (to add more voltage), place a penny and nail into a second potato, and connect the wire from the zinc nail in the first potato to the copper penny in the second. Then, add a third wire to the zinc nail in the second potato. Always remember to connect the copper (positive) end of the potato (battery) to the zinc (negative) end of the next potato (see Figure 2).

Figure 2. Activity setup to create a potato battery to power an LED clock.

1. Expect two potatoes in series to be able to light an LED; however, you might need three. Show students how to connect the LEDs to the potato in the correct manner, that is, the positive end of the LED to the negative end of the potato battery (zinc nail) and the negative end of the LED to the positive end of the potato battery (copper penny).

2. Have students discuss how the potatoes provide the electrolyte (solution) for the chemical battery to work. Ask for suggestions of other foods we could try (for example, lemons, berries, apples).

3. Ask students to complete the worksheet either individually or in pairs. After they finish, have them compare answers with a peer or another pair, giving all students time to finish.

Vocabulary/Definitions

conductor: An object that allows the transfer of electrons.

current: The movement of electrons.

electrical energy: Energy produced through the movement of electrons (voltage X current).

electrolyte: A solution that conducts electricity.

energy: The ability to do work.

insulator: An object that inhibits the transfer of electrons.

resistance: Objects or substances that prevent the passage of a steady electric current.

voltage: The amount of energy produced.

Assessment

Pre-Activity Assessment

Brainstorming: In small groups, have students engage in open discussion. Remind them that no idea or suggestion is "silly." All ideas should be respectfully heard. Take an uncritical position, encourage wild ideas and discourage criticism of ideas. Ask students how many items they can think of that run on batteries. As a class, record their ideas on the board.

Quick Poll: Before the activity begins, ask the class a question and tally their responses on the board. Ask: Can we get electrical energy from a fruit or vegetable?

Activity Embedded Assessment

Worksheet /Pairs Check: Have students work individually or in pairs on the Make a Battery Worksheet. After they finish, have them compare answers with a peer or another pair, giving all students time to finish the worksheet.

Hypothesize: Ask each group what would happen if we added more potatoes in a row to our circuits? (Answer: Adding more potatoes in a row is the same as adding batteries in a row. The voltage of each piece of potato is added up. Thus, the voltage of our circuit would increase. On the other hand, the current of our circuit would not increase. Current is not dependent on how many potatoes but is related to the size of each potato individually.)

Post-Activity Assessment

Problem Solving: Present the class with the following math problems and ask students to calculate how many of each vegetable or fruit are needed to light the bulb.

If a lemon produces 1 Volt of energy, how many lemons would you need to light a 2 Volt light bulb? (Answer: 2)

If a potato produces 0.8 Volts of energy, how many potatoes would you need to light a 1.5 Volt light bulb? (Answer: 2)

If a potato produces 0.8 Volts of energy, how many potatoes would you need to light a 3 Volt digital clock? (Answer: 4)

If you have a lemon that produces 1 Volt of energy and an apple that produces 1 Volt of energy, can you light a 3 Volt clock? (Answer: No, you would need one more lemon or apple.)

Diagramming: Engineers must understand how circuits work in order to develop cool new technologies. Draw a picture of your potato battery. Label the battery (voltage) and the resistance (light bulb). Draw an arrow to show the current flow (from the copper end to the zinc end). List two cool products that an engineer could develop that run off a fruit battery.

Troubleshooting Tips

If the LED clock, light or small light bulbs do not work, check the setup of the potato battery. Perhaps the ends are not all connected from negative to positive, or perhaps there is not enough potato voltage. Check the voltage of the potato using a multimeter or voltmeter. Another possibility is having enough voltage, but not enough current to light the bulb, which is why it is recommended to use only very low-volt LED clocks or bulbs. Also, try using more potatoes (i.e., 5 potato halves) to strengthen conductivity. Try different LED colors (for example, the blue LED may work better than the red).

Lemons and oranges also work well for this activity. They work best if you first roll them on a table top, which breaks down the cells inside so more juice flows through the fruit (current).

Some people have more conduction success using copper strips instead of copper pennies (can also wrap the pennies in copper ribbon).

Soaking the potatoes in Gatorade overnight can make them more conductive.

Activity Extensions

At activity end, before students disassemble their potato batteries, it is fun to have the entire class connect their fruit batteries in series, making "a serious tater circle."

Have students try the activity again using different fruits or vegetables! Many fruits and vegetables work, such as lemons, limes, apples and carrots. Have students compare and contrast the performance of different fruits and vegetables.

Have students complete the activity again using an electrolyte solution, such as salt water or vinegar. Have them compare and contrast the performance of different electrolyte solutions.

To add a math component, have students use the multimeter to compare the flow of electricity for several different fruits as well as to the total amount of fruits used. Ask them to graph the results and hypothesize what is happening.

Activity Scaling

Have more advanced students experiment with parallel and series configurations using different numbers of potatoes.

References

Dictionary.com. Lexico Publishing Group, LLC. Accessed September 28, 2005. (Source of some vocabulary definitions, with some adaptation) http://www.dictionary.com

Phillips, W.D. Chapter 2P: Using a Multimeter. Design Electronics (online textbook) DOCTRONICS Educational Publishing, UK. Accessed September 28, 2005. (Good design, technology and electronics resources.) http://www.doctronics.co.uk/meter.htm

Copyright © 2005 by Regents of the University of Colorado

Contributors Sharon D. Perez-Suarez; Jeff Lyng; Malinda Schaefer Zarske; Denise W. Carlson; Janet Yowell

Supporting Program Integrated Teaching and Learning Program, College of Engineering, University of Colorado Boulder

Acknowledgements

The contents of this digital library curriculum were developed under grants from the Fund for the Improvement of Postsecondary Education (FIPSE), U.S. Department of Education, and the National Science Foundation (GK-12 grant no. 0338326). However, these contents do not necessarily represent the policies of the Department of Education or National Science Foundation, and you should not assume endorsement by the federal government.

Last modified: July 9, 2020

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Students use potatoes to light an LED clock (or light bulb) as they learn how a battery works in a simple circuit and how chemical energy changes to electrical energy. As they learn more about electrical energy, they better understand the concepts of voltage, current and resistance.

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I chose this lesson because it is a fun physical way for young children to learn a lot, including math skills. It could also be used for higher elementary grades, it does not have to be limited to the lower grades.
~Sara Flood

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I've wanted to do a photo scavenger hunt with the kids for a long, long time. I always love any kind of scavenger hunt. And the boys love taking photos.

But the boys don't have their own camera, and all I have is my DSLR that I use (affiliate link) and I don't want to hand that over to the boys (I'm nervous of it breaking... and I couldn't go without it until I got it replaced).

I finally realized that the iPad mini (affiliate link) that we have can be used! Duh! It took me forever to come up with this solution.

Even better, it let me put the photo scavenger hunt right on the iPad for the kids to search for and then have George take photos of what he found.

I decided to hunt around the yard to find different shapes of objects. A square, circle, triangle and rectangle.

Triangles were the hardest to find, but found them in spokes of the cars and bikes.

Squares I found in our porch railing and skirting.

Circles were everywhere! I found a bell on their bikes, the ends of hoses, wheels of the million toys we have.

I took about a dozen photos of shapes I found around the yard and stored them in an album on the iPad for George.

George then took the iPad around the yard to find those shapes.

Once he found it, he switched over to the camera app to snap a photo of it too.

I have a collection of both my photos and his photos and its fun to compare the two!

Below is my photo for the triangle (I didn't have the red triangle and text in the photos, I just added that for this post to be clear).

And below is the photo that George took of the triangles he found.

He got the shape and object in every photo. But definitely not the same photo!

Below is my rectangle photo of a brick on the side of our house.

And below is George's version of the rectangle.

He didn't crop up nearly as close (maybe because I've told him time and time again to stay out of my plant beds and he's finally learning to listen).

This is the photo I took of the circle, a bell on his bike.

George tried to get it just the same! He did awesome hunting for them and finding the shapes!

This is his photo of the circle bell.

This photo scavenger hunt for the kids wasn't nearly as daunting as I thought it would be to put together. It took all of five minutes for me to walk around and find the shapes and snap the photos.

George loves anything to do with technology, so using the iPad to go on the scavenger hunt was a winner. Plus he got to take photos which he loves to do with it.

Got a hunter? The kids will love to go on any of these 32 ideas for scavenger hunts!

And in the meantime, he practiced his shapes. Triangles are still tough for him, but he's got squares and rectangles down now!

More move and learn ideas:

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Photo Scavenger Hunt for Kids to Find Shapes

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I've wanted to do a photo scavenger hunt with the kids for a long, long time. I always love any kind of scavenger hunt. And the boys love taking photos. But the boys don't have their own camera, and all I have is my DSLR that I use (affiliate link) and I don't want to hand that over to the boys (I'm nervous of it breaking...

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I thought this activity was entertaining simply because of the creative interest it may bring to the classroom. The idea of a potato generating electricity would sound very absurd to young kids and getting them to think critically about it would be very fun.
-Austin Miller

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Quick Look

Grade Level: 4 (3-5)

Time Required: 45 minutes

Expendable Cost/Group: US $2.00

Group Size: 3

Activity Dependency: None

Subject Areas: Physical Science, Science and Technology

NGSS Performance Expectations:

Summary Students use potatoes to light an LED clock (or light bulb) as they learn how a battery works in a simple circuit and how chemical energy changes to electrical energy. As they learn more about electrical energy, they better understand the concepts of voltage, current and resistance.
This engineering curriculum aligns to Next Generation Science Standards (NGSS).

Engineering Connection

Engineers use batteries to store energy in a wide range of situations. A solid electrolyte battery is most suitable in very extreme weather conditions, while nickel-zinc batteries work best in electric vehicles. Energy engineers continually evolve technology to improve the performance and life-cycle costs of batteries that store solar and wind energy. When designing a battery, engineers keep in mind the needs of the application, and use different substances to create current flow. They consider characteristics such as power output, ability to recharge, reliability, size, safety, heat generation, length of life cycle, abuse tolerance, cost and ability to be recycled. Isn't the power of engineering creativity amazing?

Learning Objectives

After this activity, students should be able to:

Describe the flow of electrical energy through a simple circuit.

Explain why a light bulb may take more than one battery to light up.

Explain the role of electrical engineers in the development of electricity sources and the products that use electricity.

Educational Standards

Each TeachEngineering lesson or activity is correlated to one or more K-12 science, technology, engineering or math (STEM) educational standards.

All 100,000+ K-12 STEM standards covered in TeachEngineering are collected, maintained and packaged by the Achievement Standards Network (ASN), a project of D2L (www.achievementstandards.org).

In the ASN, standards are hierarchically structured: first by source; e.g., by state; within source by type; e.g., science or mathematics; within type by subtype, then by grade, etc.

NGSS Performance Expectation

Click to view other curriculum aligned to this Performance Expectation

This activity focuses on the following Three Dimensional Learning aspects of NGSS:

Science & Engineering Practices

Disciplinary Core Ideas

Crosscutting Concepts

Make observations to produce data to serve as the basis for evidence for an explanation of a phenomenon or test a design solution.

Energy can be moved from place to place by moving objects or through sound, light, or electric currents. Energy is present whenever there are moving objects, sound, light, or heat. When objects collide, energy can be transferred from one object to another, thereby changing their motion. In such collisions, some energy is typically also transferred to the surrounding air; as a result, the air gets heated and sound is produced. Light also transfers energy from place to place. Energy can also be transferred from place to place by electric currents, which can then be used locally to produce motion, sound, heat, or light. The currents may have been produced to begin with by transforming the energy of motion into electrical energy.

Energy can be transferred in various ways and between objects.

Suggest an alignment not listed above

Materials List

To make a potato battery, each group needs:

3 copper pennies (or copper strips), one per potato

3 zinc nails; these are galvanized nails, available at hardware stores

5 insulated wires, 15-20 cm (6-8 inches) long, with alligator clips at the ends

1 low-current, light emitting diode (LED) clock (or LCD clock) requiring ~1.5 volts (or a small LED)

OR above materials can be purchased cumulatively in a kit, available online

For the entire class to share or one per team:

(optional) multimeter(s) or voltmeter(s); a multimeter measures current, voltage and resistance of a circuit; available at Radio Shack or other electronics stores or websites

Worksheets and Attachments
Visit [www.teachengineering.org/activities/view/cub_energy2_lesson04_activity2] to print or download.

Introduction/Motivation

What is electrical energy? From where does it come? Can you think of anything that needs electrical energy to work? How about lamps, music players, TVs and ovens? How do we get the power to run these devices? What role do electrical engineers play in improving our lives?

One place we can find electrical energy in our homes is at a wall outlet. So, how does electrical energy reach the wall outlet in our house? The energy comes from an electrical power plant, which usually makes electrical energy from burning fossil fuels, such as coal and oil. The heat energy from the burning fuel heats up water. When the water boils, it becomes steam, which flows through a pipe into a turbine (a wheel with blades). As the turbine spins from the steam, it turns a generator (a spinning magnet) that unbalances the charges in nearby atoms and produces a current of electricity. The electrical current flows through protected wires to our house.

How else can we power electrical appliances? That's right, from a battery. A battery works by providing electrons with a solution in which they can move around. Have you ever noticed that some batteries have a copper end that is positive (shown with a plus [+] sign) and another end that is negative (shown with a minus [-] sign)? Zinc is a metal that likes to give its electrons to copper. Usually, zinc just gives its electrons to copper and then the process stops. However, if you provide the electrons with a solution (called an electrolyte) to help them move to the copper, and you give the electrons a wire in which they can move from the copper back to the zinc, you can produce a circuit and a flowing path of electrical energy. (Note: Conventional current flows from positive to negative, so from the copper, through the wire, back to the zinc. The electrons actually flow negative to positive.)

A circuit is a complete path of electrical energy. This means that electrical energy or charge is produced or stored somewhere ( voltage) and has a path for the charge to flow (or current). Another part of a circuit is a resistance, such as a light bulb. Electrical engineers create circuits to help electrical energy perform work, such as lighting a room or keeping food cold. An appliance, light bulb or almost any device that uses electrical energy is a resistance. A resistance prevents or slows an electrical current or charge from moving. When electrical current flows through a source of resistance, it can be changed into light or heat or sound. Even though you cannot see it, the light bulb or appliance slows down the electrical charge.

Electrical engineers help develop the many modern products and appliances that require electrical energy. Electrical engineers also help create the technology used to generate the electrical energy in power plants in the first place. These engineers know a lot about circuits and they continually work to find better ways to store electrical charge and generate electrical current without using nonrenewable fossil fuels such as coal and oil. These electrical engineers are very important in almost everything we do! Essentially, electrical engineers create improvements for society and help save our planet for future generations. Today, we are going to be electrical engineers and learn more about how electrical energy works in a circuit. We are also going to look at generating electrical current from the energy stored in a potato! Do you think we can light a bulb with a potato? Let's try it!

Procedure

Background

How does a potato battery work? The copper (Cu) atoms attract electrons more than the zinc (Zn) atoms. If you place a strip of copper and a strip of zinc in contact with each other, many electrons pass from the zinc to the copper. As they concentrate on the copper, the electrons repel each other. When the force of repulsion between electrons and the force of attraction of electrons to the copper become equalized, the flow of electrons stops. Unfortunately it is not possible to take advantage of this behavior to produce electricity because the flow of charges stops almost immediately. On the other hand, if you bathe the two strips in a conductive solution, and connect them externally with a wire, the reactions between the electrodes and the solution continually furnish the circuit with charges. In this way, the process that produces the electrical energy continues and becomes useful. In a conductive solution, the charge is carried by ions that move through the solution. In the solid state, the ions are not able to move around freely. However, once they are dissolved in water, they become completely mobile. They can "swim" around in the water and thus can respond to an electric current from a battery. That current supplies electrons that cause positive ions to flow in one direction and negative ions to flow in the opposite direction. The ions carry electrical charge from one electrode to another, completing the electrical circuit.

For a conductive solution, use any electrolyte, whether it is an acid, base or salt solution. An electrolyte is a substance whose aqueous solution contains various ions and thus conducts electricity. Therefore, the more free ions a solution has, the better conductor it will be. Many fruits and vegetables contain juices rich in ions and are therefore good electrical conductors.

Like any battery, a potato battery has a limited life span. The electrodes undergo chemical reactions that block the flow of electricity. The electromotive force diminishes and the battery stops working. Usually, what happens is the production of hydrogen at the copper electrode and the zinc electrode acquires deposits of oxides that act as a barrier between the metal and the electrolyte. This is referred to as the electrodes being polarized. To achieve a longer life and higher voltages and current flows, it is necessary to use electrolytes better suited for the purpose. Commercial batteries, apart from their normal electrolyte, contain chemicals with an affinity for hydrogen, which combine with the hydrogen before it can polarize the electrodes.

Before the Activity

With the Students

1. Divide the class into teams of two or three students each. Hand out the materials.

2. Direct groups to carefully place the zinc nails and copper pennies into the potato. Make sure the two different metals do not touch each other in the potato (see Figure 1).

3. Connect one alligator clip to the end of the penny sticking out of the potato and another alligator clip to the end of the nail sticking out of the potato (see Figure 1).

Figure 1. Placement of the nail, penny and alligator clips.

1. (If you have a multimeter) Tell students that a multimeter is an instrument that measures current, voltage and resistance of a circuit, and is a tool (created by and) often used by engineers. Set the multimeter on a low "DC volts" scale for voltage and "DC milliamps" for current, so students can see the charge that one potato can produce. Expect the potato to produce just less than 1 volt. Encourage students to convert the decimal readout from the multimeter to a fraction (for example, 0.82 volts = 82/100 volts).

2. Have the students figure out how many potatoes they need to light their LED clock (or clock). For example, if their potato produces a voltage of 0.8 volts, then they may need two potatoes to power a 1.5 voltage LED.

3. Have students experiment to figure out how to connect two potatoes together. To connect two potatoes in series (to add more voltage), place a penny and nail into a second potato, and connect the wire from the zinc nail in the first potato to the copper penny in the second. Then, add a third wire to the zinc nail in the second potato. Always remember to connect the copper (positive) end of the potato (battery) to the zinc (negative) end of the next potato (see Figure 2).

Figure 2. Activity setup to create a potato battery to power an LED clock.

1. Expect two potatoes in series to be able to light an LED; however, you might need three. Show students how to connect the LEDs to the potato in the correct manner, that is, the positive end of the LED to the negative end of the potato battery (zinc nail) and the negative end of the LED to the positive end of the potato battery (copper penny).

2. Have students discuss how the potatoes provide the electrolyte (solution) for the chemical battery to work. Ask for suggestions of other foods we could try (for example, lemons, berries, apples).

3. Ask students to complete the worksheet either individually or in pairs. After they finish, have them compare answers with a peer or another pair, giving all students time to finish.

Vocabulary/Definitions

conductor: An object that allows the transfer of electrons.

current: The movement of electrons.

electrical energy: Energy produced through the movement of electrons (voltage X current).

electrolyte: A solution that conducts electricity.

energy: The ability to do work.

insulator: An object that inhibits the transfer of electrons.

resistance: Objects or substances that prevent the passage of a steady electric current.

voltage: The amount of energy produced.

Assessment

Pre-Activity Assessment

Brainstorming: In small groups, have students engage in open discussion. Remind them that no idea or suggestion is "silly." All ideas should be respectfully heard. Take an uncritical position, encourage wild ideas and discourage criticism of ideas. Ask students how many items they can think of that run on batteries. As a class, record their ideas on the board.

Quick Poll: Before the activity begins, ask the class a question and tally their responses on the board. Ask: Can we get electrical energy from a fruit or vegetable?

Activity Embedded Assessment

Worksheet /Pairs Check: Have students work individually or in pairs on the Make a Battery Worksheet. After they finish, have them compare answers with a peer or another pair, giving all students time to finish the worksheet.

Hypothesize: Ask each group what would happen if we added more potatoes in a row to our circuits? (Answer: Adding more potatoes in a row is the same as adding batteries in a row. The voltage of each piece of potato is added up. Thus, the voltage of our circuit would increase. On the other hand, the current of our circuit would not increase. Current is not dependent on how many potatoes but is related to the size of each potato individually.)

Post-Activity Assessment

Problem Solving: Present the class with the following math problems and ask students to calculate how many of each vegetable or fruit are needed to light the bulb.

If a lemon produces 1 Volt of energy, how many lemons would you need to light a 2 Volt light bulb? (Answer: 2)

If a potato produces 0.8 Volts of energy, how many potatoes would you need to light a 1.5 Volt light bulb? (Answer: 2)

If a potato produces 0.8 Volts of energy, how many potatoes would you need to light a 3 Volt digital clock? (Answer: 4)

If you have a lemon that produces 1 Volt of energy and an apple that produces 1 Volt of energy, can you light a 3 Volt clock? (Answer: No, you would need one more lemon or apple.)

Diagramming: Engineers must understand how circuits work in order to develop cool new technologies. Draw a picture of your potato battery. Label the battery (voltage) and the resistance (light bulb). Draw an arrow to show the current flow (from the copper end to the zinc end). List two cool products that an engineer could develop that run off a fruit battery.

Troubleshooting Tips

If the LED clock, light or small light bulbs do not work, check the setup of the potato battery. Perhaps the ends are not all connected from negative to positive, or perhaps there is not enough potato voltage. Check the voltage of the potato using a multimeter or voltmeter. Another possibility is having enough voltage, but not enough current to light the bulb, which is why it is recommended to use only very low-volt LED clocks or bulbs. Also, try using more potatoes (i.e., 5 potato halves) to strengthen conductivity. Try different LED colors (for example, the blue LED may work better than the red).

Lemons and oranges also work well for this activity. They work best if you first roll them on a table top, which breaks down the cells inside so more juice flows through the fruit (current).

Some people have more conduction success using copper strips instead of copper pennies (can also wrap the pennies in copper ribbon).

Soaking the potatoes in Gatorade overnight can make them more conductive.

Activity Extensions

At activity end, before students disassemble their potato batteries, it is fun to have the entire class connect their fruit batteries in series, making "a serious tater circle."

Have students try the activity again using different fruits or vegetables! Many fruits and vegetables work, such as lemons, limes, apples and carrots. Have students compare and contrast the performance of different fruits and vegetables.

Have students complete the activity again using an electrolyte solution, such as salt water or vinegar. Have them compare and contrast the performance of different electrolyte solutions.

To add a math component, have students use the multimeter to compare the flow of electricity for several different fruits as well as to the total amount of fruits used. Ask them to graph the results and hypothesize what is happening.

Activity Scaling

Have more advanced students experiment with parallel and series configurations using different numbers of potatoes.

References

Dictionary.com. Lexico Publishing Group, LLC. Accessed September 28, 2005. (Source of some vocabulary definitions, with some adaptation) http://www.dictionary.com

Phillips, W.D. Chapter 2P: Using a Multimeter. Design Electronics (online textbook) DOCTRONICS Educational Publishing, UK. Accessed September 28, 2005. (Good design, technology and electronics resources.) http://www.doctronics.co.uk/meter.htm

Copyright © 2005 by Regents of the University of Colorado

Contributors Sharon D. Perez-Suarez; Jeff Lyng; Malinda Schaefer Zarske; Denise W. Carlson; Janet Yowell

Supporting Program Integrated Teaching and Learning Program, College of Engineering, University of Colorado Boulder

Acknowledgements

The contents of this digital library curriculum were developed under grants from the Fund for the Improvement of Postsecondary Education (FIPSE), U.S. Department of Education, and the National Science Foundation (GK-12 grant no. 0338326). However, these contents do not necessarily represent the policies of the Department of Education or National Science Foundation, and you should not assume endorsement by the federal government.

Last modified: July 9, 2020

# data[].attributes.attachment_link.description
Students use potatoes to light an LED clock (or light bulb) as they learn how a battery works in a simple circuit and how chemical energy changes to electrical energy. As they learn more about electrical energy, they better understand the concepts of voltage, current and resistance.

# data[].attributes.body
I really like this because even at my age I would be excited to create power out of a potato! Also, who does not love potatoes!!

# data[].attributes.attachment_link.readable_text
Quick Look

Grade Level: 4 (3-5)

Time Required: 45 minutes

Expendable Cost/Group: US $2.00

Group Size: 3

Activity Dependency: None

Subject Areas: Physical Science, Science and Technology

NGSS Performance Expectations:

Summary Students use potatoes to light an LED clock (or light bulb) as they learn how a battery works in a simple circuit and how chemical energy changes to electrical energy. As they learn more about electrical energy, they better understand the concepts of voltage, current and resistance.
This engineering curriculum aligns to Next Generation Science Standards (NGSS).

Engineering Connection

Engineers use batteries to store energy in a wide range of situations. A solid electrolyte battery is most suitable in very extreme weather conditions, while nickel-zinc batteries work best in electric vehicles. Energy engineers continually evolve technology to improve the performance and life-cycle costs of batteries that store solar and wind energy. When designing a battery, engineers keep in mind the needs of the application, and use different substances to create current flow. They consider characteristics such as power output, ability to recharge, reliability, size, safety, heat generation, length of life cycle, abuse tolerance, cost and ability to be recycled. Isn't the power of engineering creativity amazing?

Learning Objectives

After this activity, students should be able to:

Describe the flow of electrical energy through a simple circuit.

Explain why a light bulb may take more than one battery to light up.

Explain the role of electrical engineers in the development of electricity sources and the products that use electricity.

Educational Standards

Each TeachEngineering lesson or activity is correlated to one or more K-12 science, technology, engineering or math (STEM) educational standards.

All 100,000+ K-12 STEM standards covered in TeachEngineering are collected, maintained and packaged by the Achievement Standards Network (ASN), a project of D2L (www.achievementstandards.org).

In the ASN, standards are hierarchically structured: first by source; e.g., by state; within source by type; e.g., science or mathematics; within type by subtype, then by grade, etc.

NGSS Performance Expectation

Click to view other curriculum aligned to this Performance Expectation

This activity focuses on the following Three Dimensional Learning aspects of NGSS:

Science & Engineering Practices

Disciplinary Core Ideas

Crosscutting Concepts

Make observations to produce data to serve as the basis for evidence for an explanation of a phenomenon or test a design solution.

Energy can be moved from place to place by moving objects or through sound, light, or electric currents. Energy is present whenever there are moving objects, sound, light, or heat. When objects collide, energy can be transferred from one object to another, thereby changing their motion. In such collisions, some energy is typically also transferred to the surrounding air; as a result, the air gets heated and sound is produced. Light also transfers energy from place to place. Energy can also be transferred from place to place by electric currents, which can then be used locally to produce motion, sound, heat, or light. The currents may have been produced to begin with by transforming the energy of motion into electrical energy.

Energy can be transferred in various ways and between objects.

Suggest an alignment not listed above

Materials List

To make a potato battery, each group needs:

3 copper pennies (or copper strips), one per potato

3 zinc nails; these are galvanized nails, available at hardware stores

5 insulated wires, 15-20 cm (6-8 inches) long, with alligator clips at the ends

1 low-current, light emitting diode (LED) clock (or LCD clock) requiring ~1.5 volts (or a small LED)

OR above materials can be purchased cumulatively in a kit, available online

For the entire class to share or one per team:

(optional) multimeter(s) or voltmeter(s); a multimeter measures current, voltage and resistance of a circuit; available at Radio Shack or other electronics stores or websites

Worksheets and Attachments
Visit [www.teachengineering.org/activities/view/cub_energy2_lesson04_activity2] to print or download.

Introduction/Motivation

What is electrical energy? From where does it come? Can you think of anything that needs electrical energy to work? How about lamps, music players, TVs and ovens? How do we get the power to run these devices? What role do electrical engineers play in improving our lives?

One place we can find electrical energy in our homes is at a wall outlet. So, how does electrical energy reach the wall outlet in our house? The energy comes from an electrical power plant, which usually makes electrical energy from burning fossil fuels, such as coal and oil. The heat energy from the burning fuel heats up water. When the water boils, it becomes steam, which flows through a pipe into a turbine (a wheel with blades). As the turbine spins from the steam, it turns a generator (a spinning magnet) that unbalances the charges in nearby atoms and produces a current of electricity. The electrical current flows through protected wires to our house.

How else can we power electrical appliances? That's right, from a battery. A battery works by providing electrons with a solution in which they can move around. Have you ever noticed that some batteries have a copper end that is positive (shown with a plus [+] sign) and another end that is negative (shown with a minus [-] sign)? Zinc is a metal that likes to give its electrons to copper. Usually, zinc just gives its electrons to copper and then the process stops. However, if you provide the electrons with a solution (called an electrolyte) to help them move to the copper, and you give the electrons a wire in which they can move from the copper back to the zinc, you can produce a circuit and a flowing path of electrical energy. (Note: Conventional current flows from positive to negative, so from the copper, through the wire, back to the zinc. The electrons actually flow negative to positive.)

A circuit is a complete path of electrical energy. This means that electrical energy or charge is produced or stored somewhere ( voltage) and has a path for the charge to flow (or current). Another part of a circuit is a resistance, such as a light bulb. Electrical engineers create circuits to help electrical energy perform work, such as lighting a room or keeping food cold. An appliance, light bulb or almost any device that uses electrical energy is a resistance. A resistance prevents or slows an electrical current or charge from moving. When electrical current flows through a source of resistance, it can be changed into light or heat or sound. Even though you cannot see it, the light bulb or appliance slows down the electrical charge.

Electrical engineers help develop the many modern products and appliances that require electrical energy. Electrical engineers also help create the technology used to generate the electrical energy in power plants in the first place. These engineers know a lot about circuits and they continually work to find better ways to store electrical charge and generate electrical current without using nonrenewable fossil fuels such as coal and oil. These electrical engineers are very important in almost everything we do! Essentially, electrical engineers create improvements for society and help save our planet for future generations. Today, we are going to be electrical engineers and learn more about how electrical energy works in a circuit. We are also going to look at generating electrical current from the energy stored in a potato! Do you think we can light a bulb with a potato? Let's try it!

Procedure

Background

How does a potato battery work? The copper (Cu) atoms attract electrons more than the zinc (Zn) atoms. If you place a strip of copper and a strip of zinc in contact with each other, many electrons pass from the zinc to the copper. As they concentrate on the copper, the electrons repel each other. When the force of repulsion between electrons and the force of attraction of electrons to the copper become equalized, the flow of electrons stops. Unfortunately it is not possible to take advantage of this behavior to produce electricity because the flow of charges stops almost immediately. On the other hand, if you bathe the two strips in a conductive solution, and connect them externally with a wire, the reactions between the electrodes and the solution continually furnish the circuit with charges. In this way, the process that produces the electrical energy continues and becomes useful. In a conductive solution, the charge is carried by ions that move through the solution. In the solid state, the ions are not able to move around freely. However, once they are dissolved in water, they become completely mobile. They can "swim" around in the water and thus can respond to an electric current from a battery. That current supplies electrons that cause positive ions to flow in one direction and negative ions to flow in the opposite direction. The ions carry electrical charge from one electrode to another, completing the electrical circuit.

For a conductive solution, use any electrolyte, whether it is an acid, base or salt solution. An electrolyte is a substance whose aqueous solution contains various ions and thus conducts electricity. Therefore, the more free ions a solution has, the better conductor it will be. Many fruits and vegetables contain juices rich in ions and are therefore good electrical conductors.

Like any battery, a potato battery has a limited life span. The electrodes undergo chemical reactions that block the flow of electricity. The electromotive force diminishes and the battery stops working. Usually, what happens is the production of hydrogen at the copper electrode and the zinc electrode acquires deposits of oxides that act as a barrier between the metal and the electrolyte. This is referred to as the electrodes being polarized. To achieve a longer life and higher voltages and current flows, it is necessary to use electrolytes better suited for the purpose. Commercial batteries, apart from their normal electrolyte, contain chemicals with an affinity for hydrogen, which combine with the hydrogen before it can polarize the electrodes.

Before the Activity

With the Students

1. Divide the class into teams of two or three students each. Hand out the materials.

2. Direct groups to carefully place the zinc nails and copper pennies into the potato. Make sure the two different metals do not touch each other in the potato (see Figure 1).

3. Connect one alligator clip to the end of the penny sticking out of the potato and another alligator clip to the end of the nail sticking out of the potato (see Figure 1).

Figure 1. Placement of the nail, penny and alligator clips.

1. (If you have a multimeter) Tell students that a multimeter is an instrument that measures current, voltage and resistance of a circuit, and is a tool (created by and) often used by engineers. Set the multimeter on a low "DC volts" scale for voltage and "DC milliamps" for current, so students can see the charge that one potato can produce. Expect the potato to produce just less than 1 volt. Encourage students to convert the decimal readout from the multimeter to a fraction (for example, 0.82 volts = 82/100 volts).

2. Have the students figure out how many potatoes they need to light their LED clock (or clock). For example, if their potato produces a voltage of 0.8 volts, then they may need two potatoes to power a 1.5 voltage LED.

3. Have students experiment to figure out how to connect two potatoes together. To connect two potatoes in series (to add more voltage), place a penny and nail into a second potato, and connect the wire from the zinc nail in the first potato to the copper penny in the second. Then, add a third wire to the zinc nail in the second potato. Always remember to connect the copper (positive) end of the potato (battery) to the zinc (negative) end of the next potato (see Figure 2).

Figure 2. Activity setup to create a potato battery to power an LED clock.

1. Expect two potatoes in series to be able to light an LED; however, you might need three. Show students how to connect the LEDs to the potato in the correct manner, that is, the positive end of the LED to the negative end of the potato battery (zinc nail) and the negative end of the LED to the positive end of the potato battery (copper penny).

2. Have students discuss how the potatoes provide the electrolyte (solution) for the chemical battery to work. Ask for suggestions of other foods we could try (for example, lemons, berries, apples).

3. Ask students to complete the worksheet either individually or in pairs. After they finish, have them compare answers with a peer or another pair, giving all students time to finish.

Vocabulary/Definitions

conductor: An object that allows the transfer of electrons.

current: The movement of electrons.

electrical energy: Energy produced through the movement of electrons (voltage X current).

electrolyte: A solution that conducts electricity.

energy: The ability to do work.

insulator: An object that inhibits the transfer of electrons.

resistance: Objects or substances that prevent the passage of a steady electric current.

voltage: The amount of energy produced.

Assessment

Pre-Activity Assessment

Brainstorming: In small groups, have students engage in open discussion. Remind them that no idea or suggestion is "silly." All ideas should be respectfully heard. Take an uncritical position, encourage wild ideas and discourage criticism of ideas. Ask students how many items they can think of that run on batteries. As a class, record their ideas on the board.

Quick Poll: Before the activity begins, ask the class a question and tally their responses on the board. Ask: Can we get electrical energy from a fruit or vegetable?

Activity Embedded Assessment

Worksheet /Pairs Check: Have students work individually or in pairs on the Make a Battery Worksheet. After they finish, have them compare answers with a peer or another pair, giving all students time to finish the worksheet.

Hypothesize: Ask each group what would happen if we added more potatoes in a row to our circuits? (Answer: Adding more potatoes in a row is the same as adding batteries in a row. The voltage of each piece of potato is added up. Thus, the voltage of our circuit would increase. On the other hand, the current of our circuit would not increase. Current is not dependent on how many potatoes but is related to the size of each potato individually.)

Post-Activity Assessment

Problem Solving: Present the class with the following math problems and ask students to calculate how many of each vegetable or fruit are needed to light the bulb.

If a lemon produces 1 Volt of energy, how many lemons would you need to light a 2 Volt light bulb? (Answer: 2)

If a potato produces 0.8 Volts of energy, how many potatoes would you need to light a 1.5 Volt light bulb? (Answer: 2)

If a potato produces 0.8 Volts of energy, how many potatoes would you need to light a 3 Volt digital clock? (Answer: 4)

If you have a lemon that produces 1 Volt of energy and an apple that produces 1 Volt of energy, can you light a 3 Volt clock? (Answer: No, you would need one more lemon or apple.)

Diagramming: Engineers must understand how circuits work in order to develop cool new technologies. Draw a picture of your potato battery. Label the battery (voltage) and the resistance (light bulb). Draw an arrow to show the current flow (from the copper end to the zinc end). List two cool products that an engineer could develop that run off a fruit battery.

Troubleshooting Tips

If the LED clock, light or small light bulbs do not work, check the setup of the potato battery. Perhaps the ends are not all connected from negative to positive, or perhaps there is not enough potato voltage. Check the voltage of the potato using a multimeter or voltmeter. Another possibility is having enough voltage, but not enough current to light the bulb, which is why it is recommended to use only very low-volt LED clocks or bulbs. Also, try using more potatoes (i.e., 5 potato halves) to strengthen conductivity. Try different LED colors (for example, the blue LED may work better than the red).

Lemons and oranges also work well for this activity. They work best if you first roll them on a table top, which breaks down the cells inside so more juice flows through the fruit (current).

Some people have more conduction success using copper strips instead of copper pennies (can also wrap the pennies in copper ribbon).

Soaking the potatoes in Gatorade overnight can make them more conductive.

Activity Extensions

At activity end, before students disassemble their potato batteries, it is fun to have the entire class connect their fruit batteries in series, making "a serious tater circle."

Have students try the activity again using different fruits or vegetables! Many fruits and vegetables work, such as lemons, limes, apples and carrots. Have students compare and contrast the performance of different fruits and vegetables.

Have students complete the activity again using an electrolyte solution, such as salt water or vinegar. Have them compare and contrast the performance of different electrolyte solutions.

To add a math component, have students use the multimeter to compare the flow of electricity for several different fruits as well as to the total amount of fruits used. Ask them to graph the results and hypothesize what is happening.

Activity Scaling

Have more advanced students experiment with parallel and series configurations using different numbers of potatoes.

References

Dictionary.com. Lexico Publishing Group, LLC. Accessed September 28, 2005. (Source of some vocabulary definitions, with some adaptation) http://www.dictionary.com

Phillips, W.D. Chapter 2P: Using a Multimeter. Design Electronics (online textbook) DOCTRONICS Educational Publishing, UK. Accessed September 28, 2005. (Good design, technology and electronics resources.) http://www.doctronics.co.uk/meter.htm

Copyright © 2005 by Regents of the University of Colorado

Contributors Sharon D. Perez-Suarez; Jeff Lyng; Malinda Schaefer Zarske; Denise W. Carlson; Janet Yowell

Supporting Program Integrated Teaching and Learning Program, College of Engineering, University of Colorado Boulder

Acknowledgements

The contents of this digital library curriculum were developed under grants from the Fund for the Improvement of Postsecondary Education (FIPSE), U.S. Department of Education, and the National Science Foundation (GK-12 grant no. 0338326). However, these contents do not necessarily represent the policies of the Department of Education or National Science Foundation, and you should not assume endorsement by the federal government.

Last modified: July 9, 2020

# data[].attributes.attachment_link.description
Students use potatoes to light an LED clock (or light bulb) as they learn how a battery works in a simple circuit and how chemical energy changes to electrical energy. As they learn more about electrical energy, they better understand the concepts of voltage, current and resistance.

# data[].attributes.body
I chose this lesson because it covers so many ISTE and 21st century skills. It is a really cool lesson and I think it will be cool for the students to get to make a circuit.
-Courtney Drennen.

# data[].attributes.attachment_link.readable_text
Quick Look

Grade Level: 4 (3-5)

Time Required: 45 minutes

Expendable Cost/Group: US $2.00

Group Size: 3

Activity Dependency: None

Subject Areas: Physical Science, Science and Technology

NGSS Performance Expectations:

Summary Students use potatoes to light an LED clock (or light bulb) as they learn how a battery works in a simple circuit and how chemical energy changes to electrical energy. As they learn more about electrical energy, they better understand the concepts of voltage, current and resistance.
This engineering curriculum aligns to Next Generation Science Standards (NGSS).

Engineering Connection

Engineers use batteries to store energy in a wide range of situations. A solid electrolyte battery is most suitable in very extreme weather conditions, while nickel-zinc batteries work best in electric vehicles. Energy engineers continually evolve technology to improve the performance and life-cycle costs of batteries that store solar and wind energy. When designing a battery, engineers keep in mind the needs of the application, and use different substances to create current flow. They consider characteristics such as power output, ability to recharge, reliability, size, safety, heat generation, length of life cycle, abuse tolerance, cost and ability to be recycled. Isn't the power of engineering creativity amazing?

Learning Objectives

After this activity, students should be able to:

Describe the flow of electrical energy through a simple circuit.

Explain why a light bulb may take more than one battery to light up.

Explain the role of electrical engineers in the development of electricity sources and the products that use electricity.

Educational Standards

Each TeachEngineering lesson or activity is correlated to one or more K-12 science, technology, engineering or math (STEM) educational standards.

All 100,000+ K-12 STEM standards covered in TeachEngineering are collected, maintained and packaged by the Achievement Standards Network (ASN), a project of D2L (www.achievementstandards.org).

In the ASN, standards are hierarchically structured: first by source; e.g., by state; within source by type; e.g., science or mathematics; within type by subtype, then by grade, etc.

NGSS Performance Expectation

Click to view other curriculum aligned to this Performance Expectation

This activity focuses on the following Three Dimensional Learning aspects of NGSS:

Science & Engineering Practices

Disciplinary Core Ideas

Crosscutting Concepts

Make observations to produce data to serve as the basis for evidence for an explanation of a phenomenon or test a design solution.

Energy can be moved from place to place by moving objects or through sound, light, or electric currents. Energy is present whenever there are moving objects, sound, light, or heat. When objects collide, energy can be transferred from one object to another, thereby changing their motion. In such collisions, some energy is typically also transferred to the surrounding air; as a result, the air gets heated and sound is produced. Light also transfers energy from place to place. Energy can also be transferred from place to place by electric currents, which can then be used locally to produce motion, sound, heat, or light. The currents may have been produced to begin with by transforming the energy of motion into electrical energy.

Energy can be transferred in various ways and between objects.

Suggest an alignment not listed above

Materials List

To make a potato battery, each group needs:

3 copper pennies (or copper strips), one per potato

3 zinc nails; these are galvanized nails, available at hardware stores

5 insulated wires, 15-20 cm (6-8 inches) long, with alligator clips at the ends

1 low-current, light emitting diode (LED) clock (or LCD clock) requiring ~1.5 volts (or a small LED)

OR above materials can be purchased cumulatively in a kit, available online

For the entire class to share or one per team:

(optional) multimeter(s) or voltmeter(s); a multimeter measures current, voltage and resistance of a circuit; available at Radio Shack or other electronics stores or websites

Worksheets and Attachments
Visit [www.teachengineering.org/activities/view/cub_energy2_lesson04_activity2] to print or download.

Introduction/Motivation

What is electrical energy? From where does it come? Can you think of anything that needs electrical energy to work? How about lamps, music players, TVs and ovens? How do we get the power to run these devices? What role do electrical engineers play in improving our lives?

One place we can find electrical energy in our homes is at a wall outlet. So, how does electrical energy reach the wall outlet in our house? The energy comes from an electrical power plant, which usually makes electrical energy from burning fossil fuels, such as coal and oil. The heat energy from the burning fuel heats up water. When the water boils, it becomes steam, which flows through a pipe into a turbine (a wheel with blades). As the turbine spins from the steam, it turns a generator (a spinning magnet) that unbalances the charges in nearby atoms and produces a current of electricity. The electrical current flows through protected wires to our house.

How else can we power electrical appliances? That's right, from a battery. A battery works by providing electrons with a solution in which they can move around. Have you ever noticed that some batteries have a copper end that is positive (shown with a plus [+] sign) and another end that is negative (shown with a minus [-] sign)? Zinc is a metal that likes to give its electrons to copper. Usually, zinc just gives its electrons to copper and then the process stops. However, if you provide the electrons with a solution (called an electrolyte) to help them move to the copper, and you give the electrons a wire in which they can move from the copper back to the zinc, you can produce a circuit and a flowing path of electrical energy. (Note: Conventional current flows from positive to negative, so from the copper, through the wire, back to the zinc. The electrons actually flow negative to positive.)

A circuit is a complete path of electrical energy. This means that electrical energy or charge is produced or stored somewhere ( voltage) and has a path for the charge to flow (or current). Another part of a circuit is a resistance, such as a light bulb. Electrical engineers create circuits to help electrical energy perform work, such as lighting a room or keeping food cold. An appliance, light bulb or almost any device that uses electrical energy is a resistance. A resistance prevents or slows an electrical current or charge from moving. When electrical current flows through a source of resistance, it can be changed into light or heat or sound. Even though you cannot see it, the light bulb or appliance slows down the electrical charge.

Electrical engineers help develop the many modern products and appliances that require electrical energy. Electrical engineers also help create the technology used to generate the electrical energy in power plants in the first place. These engineers know a lot about circuits and they continually work to find better ways to store electrical charge and generate electrical current without using nonrenewable fossil fuels such as coal and oil. These electrical engineers are very important in almost everything we do! Essentially, electrical engineers create improvements for society and help save our planet for future generations. Today, we are going to be electrical engineers and learn more about how electrical energy works in a circuit. We are also going to look at generating electrical current from the energy stored in a potato! Do you think we can light a bulb with a potato? Let's try it!

Procedure

Background

How does a potato battery work? The copper (Cu) atoms attract electrons more than the zinc (Zn) atoms. If you place a strip of copper and a strip of zinc in contact with each other, many electrons pass from the zinc to the copper. As they concentrate on the copper, the electrons repel each other. When the force of repulsion between electrons and the force of attraction of electrons to the copper become equalized, the flow of electrons stops. Unfortunately it is not possible to take advantage of this behavior to produce electricity because the flow of charges stops almost immediately. On the other hand, if you bathe the two strips in a conductive solution, and connect them externally with a wire, the reactions between the electrodes and the solution continually furnish the circuit with charges. In this way, the process that produces the electrical energy continues and becomes useful. In a conductive solution, the charge is carried by ions that move through the solution. In the solid state, the ions are not able to move around freely. However, once they are dissolved in water, they become completely mobile. They can "swim" around in the water and thus can respond to an electric current from a battery. That current supplies electrons that cause positive ions to flow in one direction and negative ions to flow in the opposite direction. The ions carry electrical charge from one electrode to another, completing the electrical circuit.

For a conductive solution, use any electrolyte, whether it is an acid, base or salt solution. An electrolyte is a substance whose aqueous solution contains various ions and thus conducts electricity. Therefore, the more free ions a solution has, the better conductor it will be. Many fruits and vegetables contain juices rich in ions and are therefore good electrical conductors.

Like any battery, a potato battery has a limited life span. The electrodes undergo chemical reactions that block the flow of electricity. The electromotive force diminishes and the battery stops working. Usually, what happens is the production of hydrogen at the copper electrode and the zinc electrode acquires deposits of oxides that act as a barrier between the metal and the electrolyte. This is referred to as the electrodes being polarized. To achieve a longer life and higher voltages and current flows, it is necessary to use electrolytes better suited for the purpose. Commercial batteries, apart from their normal electrolyte, contain chemicals with an affinity for hydrogen, which combine with the hydrogen before it can polarize the electrodes.

Before the Activity

With the Students

1. Divide the class into teams of two or three students each. Hand out the materials.

2. Direct groups to carefully place the zinc nails and copper pennies into the potato. Make sure the two different metals do not touch each other in the potato (see Figure 1).

3. Connect one alligator clip to the end of the penny sticking out of the potato and another alligator clip to the end of the nail sticking out of the potato (see Figure 1).

Figure 1. Placement of the nail, penny and alligator clips.

1. (If you have a multimeter) Tell students that a multimeter is an instrument that measures current, voltage and resistance of a circuit, and is a tool (created by and) often used by engineers. Set the multimeter on a low "DC volts" scale for voltage and "DC milliamps" for current, so students can see the charge that one potato can produce. Expect the potato to produce just less than 1 volt. Encourage students to convert the decimal readout from the multimeter to a fraction (for example, 0.82 volts = 82/100 volts).

2. Have the students figure out how many potatoes they need to light their LED clock (or clock). For example, if their potato produces a voltage of 0.8 volts, then they may need two potatoes to power a 1.5 voltage LED.

3. Have students experiment to figure out how to connect two potatoes together. To connect two potatoes in series (to add more voltage), place a penny and nail into a second potato, and connect the wire from the zinc nail in the first potato to the copper penny in the second. Then, add a third wire to the zinc nail in the second potato. Always remember to connect the copper (positive) end of the potato (battery) to the zinc (negative) end of the next potato (see Figure 2).

Figure 2. Activity setup to create a potato battery to power an LED clock.

1. Expect two potatoes in series to be able to light an LED; however, you might need three. Show students how to connect the LEDs to the potato in the correct manner, that is, the positive end of the LED to the negative end of the potato battery (zinc nail) and the negative end of the LED to the positive end of the potato battery (copper penny).

2. Have students discuss how the potatoes provide the electrolyte (solution) for the chemical battery to work. Ask for suggestions of other foods we could try (for example, lemons, berries, apples).

3. Ask students to complete the worksheet either individually or in pairs. After they finish, have them compare answers with a peer or another pair, giving all students time to finish.

Vocabulary/Definitions

conductor: An object that allows the transfer of electrons.

current: The movement of electrons.

electrical energy: Energy produced through the movement of electrons (voltage X current).

electrolyte: A solution that conducts electricity.

energy: The ability to do work.

insulator: An object that inhibits the transfer of electrons.

resistance: Objects or substances that prevent the passage of a steady electric current.

voltage: The amount of energy produced.

Assessment

Pre-Activity Assessment

Brainstorming: In small groups, have students engage in open discussion. Remind them that no idea or suggestion is "silly." All ideas should be respectfully heard. Take an uncritical position, encourage wild ideas and discourage criticism of ideas. Ask students how many items they can think of that run on batteries. As a class, record their ideas on the board.

Quick Poll: Before the activity begins, ask the class a question and tally their responses on the board. Ask: Can we get electrical energy from a fruit or vegetable?

Activity Embedded Assessment

Worksheet /Pairs Check: Have students work individually or in pairs on the Make a Battery Worksheet. After they finish, have them compare answers with a peer or another pair, giving all students time to finish the worksheet.

Hypothesize: Ask each group what would happen if we added more potatoes in a row to our circuits? (Answer: Adding more potatoes in a row is the same as adding batteries in a row. The voltage of each piece of potato is added up. Thus, the voltage of our circuit would increase. On the other hand, the current of our circuit would not increase. Current is not dependent on how many potatoes but is related to the size of each potato individually.)

Post-Activity Assessment

Problem Solving: Present the class with the following math problems and ask students to calculate how many of each vegetable or fruit are needed to light the bulb.

If a lemon produces 1 Volt of energy, how many lemons would you need to light a 2 Volt light bulb? (Answer: 2)

If a potato produces 0.8 Volts of energy, how many potatoes would you need to light a 1.5 Volt light bulb? (Answer: 2)

If a potato produces 0.8 Volts of energy, how many potatoes would you need to light a 3 Volt digital clock? (Answer: 4)

If you have a lemon that produces 1 Volt of energy and an apple that produces 1 Volt of energy, can you light a 3 Volt clock? (Answer: No, you would need one more lemon or apple.)

Diagramming: Engineers must understand how circuits work in order to develop cool new technologies. Draw a picture of your potato battery. Label the battery (voltage) and the resistance (light bulb). Draw an arrow to show the current flow (from the copper end to the zinc end). List two cool products that an engineer could develop that run off a fruit battery.

Troubleshooting Tips

If the LED clock, light or small light bulbs do not work, check the setup of the potato battery. Perhaps the ends are not all connected from negative to positive, or perhaps there is not enough potato voltage. Check the voltage of the potato using a multimeter or voltmeter. Another possibility is having enough voltage, but not enough current to light the bulb, which is why it is recommended to use only very low-volt LED clocks or bulbs. Also, try using more potatoes (i.e., 5 potato halves) to strengthen conductivity. Try different LED colors (for example, the blue LED may work better than the red).

Lemons and oranges also work well for this activity. They work best if you first roll them on a table top, which breaks down the cells inside so more juice flows through the fruit (current).

Some people have more conduction success using copper strips instead of copper pennies (can also wrap the pennies in copper ribbon).

Soaking the potatoes in Gatorade overnight can make them more conductive.

Activity Extensions

At activity end, before students disassemble their potato batteries, it is fun to have the entire class connect their fruit batteries in series, making "a serious tater circle."

Have students try the activity again using different fruits or vegetables! Many fruits and vegetables work, such as lemons, limes, apples and carrots. Have students compare and contrast the performance of different fruits and vegetables.

Have students complete the activity again using an electrolyte solution, such as salt water or vinegar. Have them compare and contrast the performance of different electrolyte solutions.

To add a math component, have students use the multimeter to compare the flow of electricity for several different fruits as well as to the total amount of fruits used. Ask them to graph the results and hypothesize what is happening.

Activity Scaling

Have more advanced students experiment with parallel and series configurations using different numbers of potatoes.

References

Dictionary.com. Lexico Publishing Group, LLC. Accessed September 28, 2005. (Source of some vocabulary definitions, with some adaptation) http://www.dictionary.com

Phillips, W.D. Chapter 2P: Using a Multimeter. Design Electronics (online textbook) DOCTRONICS Educational Publishing, UK. Accessed September 28, 2005. (Good design, technology and electronics resources.) http://www.doctronics.co.uk/meter.htm

Copyright © 2005 by Regents of the University of Colorado

Contributors Sharon D. Perez-Suarez; Jeff Lyng; Malinda Schaefer Zarske; Denise W. Carlson; Janet Yowell

Supporting Program Integrated Teaching and Learning Program, College of Engineering, University of Colorado Boulder

Acknowledgements

The contents of this digital library curriculum were developed under grants from the Fund for the Improvement of Postsecondary Education (FIPSE), U.S. Department of Education, and the National Science Foundation (GK-12 grant no. 0338326). However, these contents do not necessarily represent the policies of the Department of Education or National Science Foundation, and you should not assume endorsement by the federal government.

Last modified: July 9, 2020

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Students use potatoes to light an LED clock (or light bulb) as they learn how a battery works in a simple circuit and how chemical energy changes to electrical energy. As they learn more about electrical energy, they better understand the concepts of voltage, current and resistance.

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I picked this lesson because it demonstrates elasticity, potential energy and kinetic energy. It fosters 21st Century Skills such as communication, collaboration and critical thinking as students work together. 

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I picked this lesson because it demonstrates elasticity, potential energy and kinetic energy. It fosters 21st Century Skills such as communication, collaboration and critical thinking as students work together. 

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-Jackie Flick

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Posted on by ASEE

(Lesson Courtesy COSI Columbus - The Center for Science and Industry). Level: Grades 4 - 8. Time required: 30 to 50 minutes. Click HERE for PDF of activity. Click HERE for version developed by Ohio State University engineering graduate students and Maize Elementary teachers

Overview

This simple catapult activity for students in grades 4 - 8 teaches them how energy is transferred when a plastic spoon is pulled back, then released, rocketing its payload - a single marshmallow.

Background

What's going on? The plastic spoon has an inherent elasticity, which means it will return to its original shape after being deformed. Rubber bands and other elastic objects also have this property. When the spoon is deformed, the force used to cause that deformation is "stored" in the spoon as elastic potential energy. When the spoon is released, the elastic potential energy changes to kinetic energy as the spoon returns to its original shape, carrying the marshmallow along with it. The marshmallow continues to move after the spoon has stopped due to its inertia.

Catapult Information

(from the Museum of Ancient Inventions, Smith College)

The catapult was an ancient siege machine that could hurl heavy objects or shoot arrows with great force and for considerable distances. Some catapults could throw stones weighing as much as 350 pounds for distances greater than 300 feet.

The Greek Dionysius the Elder of Syracuse, who was looking to develop a new type of weapon, invented the catapult about 400 BCE. Thereafter, it became a key weapon in warfare and remained so up through mediaeval times. Two major catapults evolved from Dionysius's invention: the double-armed machine, or ballista, used for shooting arrows, and the single-armed catapult designed for hurling large objects. Although the Romans added wheels to both types of catapult for maneuverability, very little in the design of the machine changed.The reconstruction shown here is of a single-armed stone-hurling catapult, approximately two feet long and one-and-a-half feet tall. Its hurling arm is driven by a cocked, winch-pulled cord.

Standards (Ohio)

Physical Science: 1.6, 3.3, 3.4, 7.2, 7.4

Vocabulary

elasticity, potential energy, kinetic energy, deflection angle

Materials

Plastic spoon

1-2 bags of miniature marshmallows

marking pens

tape measure or meter stick

masking tape

protractor

safety goggles

Procedure
Instruction for teachers:
Set up the classroom so that you have at least 20 feet of open space in front of the launching area for a landing area. Have students put on goggles, then align teams of 3-4 students along one side of a set of long tables or a counter so the catapults will be aimed across the room.

Distribute to each group safety goggles, spoons, marshmallows, protractors, and lengths of masking tape.
Instructions for students:
1. Prepare your catapult by taping a spoon firmly against the edge of a table, perpendicular to the tabletop with the bowl of the spoon facing toward the table.

2. Mark your marshmallows for identification with a pen, using your group initials.

3. Test the setup of your catapult and marshmallow: Hold the marshmallow in the bowl of the spoon. Use your thumb to help anchor the spoon handle against the table.

4. Practice launch: Keeping the end of the spoon handle against the table, launching the marshmallow across the room. (Don't point it at anyone!)

5. Experiment with pulling the spoon back farther to change the angle - what are the results?

Now, determine the best deflection angle - how far you pull back the spoon - to launch the marshmallow the farthest possible distance. Decide how much to deflect the spoon, using a protractor to measure the angle between the spoon and the table. Record the measurements of your deflection angle on a sheet of paper, then launch your marshmallow and measure the distance it travels. Repeat this two more times and compute the average of the three.

6. Now, change the deflection angle of the catapult and repeat. Record the average distance for three separate different catapult angles. Record your results. What angle between the spoon and table launches the marshmallow the farthest?

7. Based on your data, predict the optimum deflection angle.

8. Hold a class contest to find out who can make a marshmallow fly the farthest.

Extensions

Ask the class what would happen if they changed the weight/size of the marshmallow - and how could they do that? Which other techniques could makes the marshmallow go farther? Higher?

Spoons may be made of several different types of plastic. Bring in other plastic spoons and try this experiment. Compare and contrast the results. Look up the properties of the different types of plastic and relate these properties to the results.

For homework, challenge students to come up with their own catapult design - still using the marshmallow load - then allow them to construct, test, and demonstrate their models in class the next day. What innovative solutions did each group devise? Have students evaluate their results and those of their classmates.

Assign students to research the history of catapults. When were they used, and for what purposes?

Resources

More ancient inventions at Smith College's online Museum of Ancient Inventions
http://www.middle-ages.org.uk/catapults.htm http://www.medieval-castle-siege-weapons.com/medieval-catapults.html
Filed under: Class Activities, Grades 6-8, Grades K-5, Grades K-5, Lesson Plans

Tags: catapult, Class Activities, forces and motion, Fun & Games, Grades 4 - 8, Grades K-5, Newton's Laws, Physical Science, Physics, trebuchet

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eGFI - For Teachers " Activity: Catapult Marshmallow Launch

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Posted on by ASEE (Lesson Courtesy COSI Columbus - The Center for Science and Industry). Level: Grades 4 - 8. Time required: 30 to 50 minutes. Click HERE for PDF of activity.

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I chose this lesson because kids get to use potatoes to learn about energy. I think it is super cool that the energy can flow through the potato and kids will be amazed by it too! It also hits on many common core standards and ISTE standards with the materials needed!
-Alexis Cancila

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Quick Look

Grade Level: 4 (3-5)

Time Required: 45 minutes

Expendable Cost/Group: US $2.00

Group Size: 3

Activity Dependency: None

Subject Areas: Physical Science, Science and Technology

NGSS Performance Expectations:

Summary Students use potatoes to light an LED clock (or light bulb) as they learn how a battery works in a simple circuit and how chemical energy changes to electrical energy. As they learn more about electrical energy, they better understand the concepts of voltage, current and resistance.
This engineering curriculum aligns to Next Generation Science Standards (NGSS).

Engineering Connection

Engineers use batteries to store energy in a wide range of situations. A solid electrolyte battery is most suitable in very extreme weather conditions, while nickel-zinc batteries work best in electric vehicles. Energy engineers continually evolve technology to improve the performance and life-cycle costs of batteries that store solar and wind energy. When designing a battery, engineers keep in mind the needs of the application, and use different substances to create current flow. They consider characteristics such as power output, ability to recharge, reliability, size, safety, heat generation, length of life cycle, abuse tolerance, cost and ability to be recycled. Isn't the power of engineering creativity amazing?

Learning Objectives

After this activity, students should be able to:

Describe the flow of electrical energy through a simple circuit.

Explain why a light bulb may take more than one battery to light up.

Explain the role of electrical engineers in the development of electricity sources and the products that use electricity.

Educational Standards

Each TeachEngineering lesson or activity is correlated to one or more K-12 science, technology, engineering or math (STEM) educational standards.

All 100,000+ K-12 STEM standards covered in TeachEngineering are collected, maintained and packaged by the Achievement Standards Network (ASN), a project of D2L (www.achievementstandards.org).

In the ASN, standards are hierarchically structured: first by source; e.g., by state; within source by type; e.g., science or mathematics; within type by subtype, then by grade, etc.

NGSS Performance Expectation

Click to view other curriculum aligned to this Performance Expectation

This activity focuses on the following Three Dimensional Learning aspects of NGSS:

Science & Engineering Practices

Disciplinary Core Ideas

Crosscutting Concepts

Make observations to produce data to serve as the basis for evidence for an explanation of a phenomenon or test a design solution.

Energy can be moved from place to place by moving objects or through sound, light, or electric currents. Energy is present whenever there are moving objects, sound, light, or heat. When objects collide, energy can be transferred from one object to another, thereby changing their motion. In such collisions, some energy is typically also transferred to the surrounding air; as a result, the air gets heated and sound is produced. Light also transfers energy from place to place. Energy can also be transferred from place to place by electric currents, which can then be used locally to produce motion, sound, heat, or light. The currents may have been produced to begin with by transforming the energy of motion into electrical energy.

Energy can be transferred in various ways and between objects.

Suggest an alignment not listed above

Materials List

To make a potato battery, each group needs:

3 copper pennies (or copper strips), one per potato

3 zinc nails; these are galvanized nails, available at hardware stores

5 insulated wires, 15-20 cm (6-8 inches) long, with alligator clips at the ends

1 low-current, light emitting diode (LED) clock (or LCD clock) requiring ~1.5 volts (or a small LED)

OR above materials can be purchased cumulatively in a kit, available online

For the entire class to share or one per team:

(optional) multimeter(s) or voltmeter(s); a multimeter measures current, voltage and resistance of a circuit; available at Radio Shack or other electronics stores or websites

Worksheets and Attachments
Visit [www.teachengineering.org/activities/view/cub_energy2_lesson04_activity2] to print or download.

Introduction/Motivation

What is electrical energy? From where does it come? Can you think of anything that needs electrical energy to work? How about lamps, music players, TVs and ovens? How do we get the power to run these devices? What role do electrical engineers play in improving our lives?

One place we can find electrical energy in our homes is at a wall outlet. So, how does electrical energy reach the wall outlet in our house? The energy comes from an electrical power plant, which usually makes electrical energy from burning fossil fuels, such as coal and oil. The heat energy from the burning fuel heats up water. When the water boils, it becomes steam, which flows through a pipe into a turbine (a wheel with blades). As the turbine spins from the steam, it turns a generator (a spinning magnet) that unbalances the charges in nearby atoms and produces a current of electricity. The electrical current flows through protected wires to our house.

How else can we power electrical appliances? That's right, from a battery. A battery works by providing electrons with a solution in which they can move around. Have you ever noticed that some batteries have a copper end that is positive (shown with a plus [+] sign) and another end that is negative (shown with a minus [-] sign)? Zinc is a metal that likes to give its electrons to copper. Usually, zinc just gives its electrons to copper and then the process stops. However, if you provide the electrons with a solution (called an electrolyte) to help them move to the copper, and you give the electrons a wire in which they can move from the copper back to the zinc, you can produce a circuit and a flowing path of electrical energy. (Note: Conventional current flows from positive to negative, so from the copper, through the wire, back to the zinc. The electrons actually flow negative to positive.)

A circuit is a complete path of electrical energy. This means that electrical energy or charge is produced or stored somewhere ( voltage) and has a path for the charge to flow (or current). Another part of a circuit is a resistance, such as a light bulb. Electrical engineers create circuits to help electrical energy perform work, such as lighting a room or keeping food cold. An appliance, light bulb or almost any device that uses electrical energy is a resistance. A resistance prevents or slows an electrical current or charge from moving. When electrical current flows through a source of resistance, it can be changed into light or heat or sound. Even though you cannot see it, the light bulb or appliance slows down the electrical charge.

Electrical engineers help develop the many modern products and appliances that require electrical energy. Electrical engineers also help create the technology used to generate the electrical energy in power plants in the first place. These engineers know a lot about circuits and they continually work to find better ways to store electrical charge and generate electrical current without using nonrenewable fossil fuels such as coal and oil. These electrical engineers are very important in almost everything we do! Essentially, electrical engineers create improvements for society and help save our planet for future generations. Today, we are going to be electrical engineers and learn more about how electrical energy works in a circuit. We are also going to look at generating electrical current from the energy stored in a potato! Do you think we can light a bulb with a potato? Let's try it!

Procedure

Background

How does a potato battery work? The copper (Cu) atoms attract electrons more than the zinc (Zn) atoms. If you place a strip of copper and a strip of zinc in contact with each other, many electrons pass from the zinc to the copper. As they concentrate on the copper, the electrons repel each other. When the force of repulsion between electrons and the force of attraction of electrons to the copper become equalized, the flow of electrons stops. Unfortunately it is not possible to take advantage of this behavior to produce electricity because the flow of charges stops almost immediately. On the other hand, if you bathe the two strips in a conductive solution, and connect them externally with a wire, the reactions between the electrodes and the solution continually furnish the circuit with charges. In this way, the process that produces the electrical energy continues and becomes useful. In a conductive solution, the charge is carried by ions that move through the solution. In the solid state, the ions are not able to move around freely. However, once they are dissolved in water, they become completely mobile. They can "swim" around in the water and thus can respond to an electric current from a battery. That current supplies electrons that cause positive ions to flow in one direction and negative ions to flow in the opposite direction. The ions carry electrical charge from one electrode to another, completing the electrical circuit.

For a conductive solution, use any electrolyte, whether it is an acid, base or salt solution. An electrolyte is a substance whose aqueous solution contains various ions and thus conducts electricity. Therefore, the more free ions a solution has, the better conductor it will be. Many fruits and vegetables contain juices rich in ions and are therefore good electrical conductors.

Like any battery, a potato battery has a limited life span. The electrodes undergo chemical reactions that block the flow of electricity. The electromotive force diminishes and the battery stops working. Usually, what happens is the production of hydrogen at the copper electrode and the zinc electrode acquires deposits of oxides that act as a barrier between the metal and the electrolyte. This is referred to as the electrodes being polarized. To achieve a longer life and higher voltages and current flows, it is necessary to use electrolytes better suited for the purpose. Commercial batteries, apart from their normal electrolyte, contain chemicals with an affinity for hydrogen, which combine with the hydrogen before it can polarize the electrodes.

Before the Activity

With the Students

1. Divide the class into teams of two or three students each. Hand out the materials.

2. Direct groups to carefully place the zinc nails and copper pennies into the potato. Make sure the two different metals do not touch each other in the potato (see Figure 1).

3. Connect one alligator clip to the end of the penny sticking out of the potato and another alligator clip to the end of the nail sticking out of the potato (see Figure 1).

Figure 1. Placement of the nail, penny and alligator clips.

1. (If you have a multimeter) Tell students that a multimeter is an instrument that measures current, voltage and resistance of a circuit, and is a tool (created by and) often used by engineers. Set the multimeter on a low "DC volts" scale for voltage and "DC milliamps" for current, so students can see the charge that one potato can produce. Expect the potato to produce just less than 1 volt. Encourage students to convert the decimal readout from the multimeter to a fraction (for example, 0.82 volts = 82/100 volts).

2. Have the students figure out how many potatoes they need to light their LED clock (or clock). For example, if their potato produces a voltage of 0.8 volts, then they may need two potatoes to power a 1.5 voltage LED.

3. Have students experiment to figure out how to connect two potatoes together. To connect two potatoes in series (to add more voltage), place a penny and nail into a second potato, and connect the wire from the zinc nail in the first potato to the copper penny in the second. Then, add a third wire to the zinc nail in the second potato. Always remember to connect the copper (positive) end of the potato (battery) to the zinc (negative) end of the next potato (see Figure 2).

Figure 2. Activity setup to create a potato battery to power an LED clock.

1. Expect two potatoes in series to be able to light an LED; however, you might need three. Show students how to connect the LEDs to the potato in the correct manner, that is, the positive end of the LED to the negative end of the potato battery (zinc nail) and the negative end of the LED to the positive end of the potato battery (copper penny).

2. Have students discuss how the potatoes provide the electrolyte (solution) for the chemical battery to work. Ask for suggestions of other foods we could try (for example, lemons, berries, apples).

3. Ask students to complete the worksheet either individually or in pairs. After they finish, have them compare answers with a peer or another pair, giving all students time to finish.

Vocabulary/Definitions

conductor: An object that allows the transfer of electrons.

current: The movement of electrons.

electrical energy: Energy produced through the movement of electrons (voltage X current).

electrolyte: A solution that conducts electricity.

energy: The ability to do work.

insulator: An object that inhibits the transfer of electrons.

resistance: Objects or substances that prevent the passage of a steady electric current.

voltage: The amount of energy produced.

Assessment

Pre-Activity Assessment

Brainstorming: In small groups, have students engage in open discussion. Remind them that no idea or suggestion is "silly." All ideas should be respectfully heard. Take an uncritical position, encourage wild ideas and discourage criticism of ideas. Ask students how many items they can think of that run on batteries. As a class, record their ideas on the board.

Quick Poll: Before the activity begins, ask the class a question and tally their responses on the board. Ask: Can we get electrical energy from a fruit or vegetable?

Activity Embedded Assessment

Worksheet /Pairs Check: Have students work individually or in pairs on the Make a Battery Worksheet. After they finish, have them compare answers with a peer or another pair, giving all students time to finish the worksheet.

Hypothesize: Ask each group what would happen if we added more potatoes in a row to our circuits? (Answer: Adding more potatoes in a row is the same as adding batteries in a row. The voltage of each piece of potato is added up. Thus, the voltage of our circuit would increase. On the other hand, the current of our circuit would not increase. Current is not dependent on how many potatoes but is related to the size of each potato individually.)

Post-Activity Assessment

Problem Solving: Present the class with the following math problems and ask students to calculate how many of each vegetable or fruit are needed to light the bulb.

If a lemon produces 1 Volt of energy, how many lemons would you need to light a 2 Volt light bulb? (Answer: 2)

If a potato produces 0.8 Volts of energy, how many potatoes would you need to light a 1.5 Volt light bulb? (Answer: 2)

If a potato produces 0.8 Volts of energy, how many potatoes would you need to light a 3 Volt digital clock? (Answer: 4)

If you have a lemon that produces 1 Volt of energy and an apple that produces 1 Volt of energy, can you light a 3 Volt clock? (Answer: No, you would need one more lemon or apple.)

Diagramming: Engineers must understand how circuits work in order to develop cool new technologies. Draw a picture of your potato battery. Label the battery (voltage) and the resistance (light bulb). Draw an arrow to show the current flow (from the copper end to the zinc end). List two cool products that an engineer could develop that run off a fruit battery.

Troubleshooting Tips

If the LED clock, light or small light bulbs do not work, check the setup of the potato battery. Perhaps the ends are not all connected from negative to positive, or perhaps there is not enough potato voltage. Check the voltage of the potato using a multimeter or voltmeter. Another possibility is having enough voltage, but not enough current to light the bulb, which is why it is recommended to use only very low-volt LED clocks or bulbs. Also, try using more potatoes (i.e., 5 potato halves) to strengthen conductivity. Try different LED colors (for example, the blue LED may work better than the red).

Lemons and oranges also work well for this activity. They work best if you first roll them on a table top, which breaks down the cells inside so more juice flows through the fruit (current).

Some people have more conduction success using copper strips instead of copper pennies (can also wrap the pennies in copper ribbon).

Soaking the potatoes in Gatorade overnight can make them more conductive.

Activity Extensions

At activity end, before students disassemble their potato batteries, it is fun to have the entire class connect their fruit batteries in series, making "a serious tater circle."

Have students try the activity again using different fruits or vegetables! Many fruits and vegetables work, such as lemons, limes, apples and carrots. Have students compare and contrast the performance of different fruits and vegetables.

Have students complete the activity again using an electrolyte solution, such as salt water or vinegar. Have them compare and contrast the performance of different electrolyte solutions.

To add a math component, have students use the multimeter to compare the flow of electricity for several different fruits as well as to the total amount of fruits used. Ask them to graph the results and hypothesize what is happening.

Activity Scaling

Have more advanced students experiment with parallel and series configurations using different numbers of potatoes.

References

Dictionary.com. Lexico Publishing Group, LLC. Accessed September 28, 2005. (Source of some vocabulary definitions, with some adaptation) http://www.dictionary.com

Phillips, W.D. Chapter 2P: Using a Multimeter. Design Electronics (online textbook) DOCTRONICS Educational Publishing, UK. Accessed September 28, 2005. (Good design, technology and electronics resources.) http://www.doctronics.co.uk/meter.htm

Copyright © 2005 by Regents of the University of Colorado

Contributors Sharon D. Perez-Suarez; Jeff Lyng; Malinda Schaefer Zarske; Denise W. Carlson; Janet Yowell

Supporting Program Integrated Teaching and Learning Program, College of Engineering, University of Colorado Boulder

Acknowledgements

The contents of this digital library curriculum were developed under grants from the Fund for the Improvement of Postsecondary Education (FIPSE), U.S. Department of Education, and the National Science Foundation (GK-12 grant no. 0338326). However, these contents do not necessarily represent the policies of the Department of Education or National Science Foundation, and you should not assume endorsement by the federal government.

Last modified: July 9, 2020

# data[].attributes.attachment_link.description
Students use potatoes to light an LED clock (or light bulb) as they learn how a battery works in a simple circuit and how chemical energy changes to electrical energy. As they learn more about electrical energy, they better understand the concepts of voltage, current and resistance.

# data[].attributes.body
I would enjoy using this activity in my classroom because the materials are super simple. Another reason why I like this activity is because it includes that engineering part of STEM and you do not see too much of that in classrooms.
- Victoria Malpica

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Posted on by ASEE

(Lesson Courtesy COSI Columbus - The Center for Science and Industry). Level: Grades 4 - 8. Time required: 30 to 50 minutes. Click HERE for PDF of activity. Click HERE for version developed by Ohio State University engineering graduate students and Maize Elementary teachers

Overview

This simple catapult activity for students in grades 4 - 8 teaches them how energy is transferred when a plastic spoon is pulled back, then released, rocketing its payload - a single marshmallow.

Background

What's going on? The plastic spoon has an inherent elasticity, which means it will return to its original shape after being deformed. Rubber bands and other elastic objects also have this property. When the spoon is deformed, the force used to cause that deformation is "stored" in the spoon as elastic potential energy. When the spoon is released, the elastic potential energy changes to kinetic energy as the spoon returns to its original shape, carrying the marshmallow along with it. The marshmallow continues to move after the spoon has stopped due to its inertia.

Catapult Information

(from the Museum of Ancient Inventions, Smith College)

The catapult was an ancient siege machine that could hurl heavy objects or shoot arrows with great force and for considerable distances. Some catapults could throw stones weighing as much as 350 pounds for distances greater than 300 feet.

The Greek Dionysius the Elder of Syracuse, who was looking to develop a new type of weapon, invented the catapult about 400 BCE. Thereafter, it became a key weapon in warfare and remained so up through mediaeval times. Two major catapults evolved from Dionysius's invention: the double-armed machine, or ballista, used for shooting arrows, and the single-armed catapult designed for hurling large objects. Although the Romans added wheels to both types of catapult for maneuverability, very little in the design of the machine changed.The reconstruction shown here is of a single-armed stone-hurling catapult, approximately two feet long and one-and-a-half feet tall. Its hurling arm is driven by a cocked, winch-pulled cord.

Standards (Ohio)

Physical Science: 1.6, 3.3, 3.4, 7.2, 7.4

Vocabulary

elasticity, potential energy, kinetic energy, deflection angle

Materials

Plastic spoon

1-2 bags of miniature marshmallows

marking pens

tape measure or meter stick

masking tape

protractor

safety goggles

Procedure
Instruction for teachers:
Set up the classroom so that you have at least 20 feet of open space in front of the launching area for a landing area. Have students put on goggles, then align teams of 3-4 students along one side of a set of long tables or a counter so the catapults will be aimed across the room.

Distribute to each group safety goggles, spoons, marshmallows, protractors, and lengths of masking tape.
Instructions for students:
1. Prepare your catapult by taping a spoon firmly against the edge of a table, perpendicular to the tabletop with the bowl of the spoon facing toward the table.

2. Mark your marshmallows for identification with a pen, using your group initials.

3. Test the setup of your catapult and marshmallow: Hold the marshmallow in the bowl of the spoon. Use your thumb to help anchor the spoon handle against the table.

4. Practice launch: Keeping the end of the spoon handle against the table, launching the marshmallow across the room. (Don't point it at anyone!)

5. Experiment with pulling the spoon back farther to change the angle - what are the results?

Now, determine the best deflection angle - how far you pull back the spoon - to launch the marshmallow the farthest possible distance. Decide how much to deflect the spoon, using a protractor to measure the angle between the spoon and the table. Record the measurements of your deflection angle on a sheet of paper, then launch your marshmallow and measure the distance it travels. Repeat this two more times and compute the average of the three.

6. Now, change the deflection angle of the catapult and repeat. Record the average distance for three separate different catapult angles. Record your results. What angle between the spoon and table launches the marshmallow the farthest?

7. Based on your data, predict the optimum deflection angle.

8. Hold a class contest to find out who can make a marshmallow fly the farthest.

Extensions

Ask the class what would happen if they changed the weight/size of the marshmallow - and how could they do that? Which other techniques could makes the marshmallow go farther? Higher?

Spoons may be made of several different types of plastic. Bring in other plastic spoons and try this experiment. Compare and contrast the results. Look up the properties of the different types of plastic and relate these properties to the results.

For homework, challenge students to come up with their own catapult design - still using the marshmallow load - then allow them to construct, test, and demonstrate their models in class the next day. What innovative solutions did each group devise? Have students evaluate their results and those of their classmates.

Assign students to research the history of catapults. When were they used, and for what purposes?

Resources

More ancient inventions at Smith College's online Museum of Ancient Inventions
http://www.middle-ages.org.uk/catapults.htm http://www.medieval-castle-siege-weapons.com/medieval-catapults.html
Filed under: Class Activities, Grades 6-8, Grades K-5, Grades K-5, Lesson Plans

Tags: catapult, Class Activities, forces and motion, Fun & Games, Grades 4 - 8, Grades K-5, Newton's Laws, Physical Science, Physics, trebuchet

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eGFI - For Teachers " Activity: Catapult Marshmallow Launch

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Posted on by ASEE (Lesson Courtesy COSI Columbus - The Center for Science and Industry). Level: Grades 4 - 8. Time required: 30 to 50 minutes. Click HERE for PDF of activity.

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I chose this lesson because it seems like a fun way to make a circuit. It also covers many ISTE Standards, and 21st Century Skills.
~Sara Flood

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Quick Look

Grade Level: 4 (3-5)

Time Required: 45 minutes

Expendable Cost/Group: US $2.00

Group Size: 3

Activity Dependency: None

Subject Areas: Physical Science, Science and Technology

NGSS Performance Expectations:

Summary Students use potatoes to light an LED clock (or light bulb) as they learn how a battery works in a simple circuit and how chemical energy changes to electrical energy. As they learn more about electrical energy, they better understand the concepts of voltage, current and resistance.
This engineering curriculum aligns to Next Generation Science Standards (NGSS).

Engineering Connection

Engineers use batteries to store energy in a wide range of situations. A solid electrolyte battery is most suitable in very extreme weather conditions, while nickel-zinc batteries work best in electric vehicles. Energy engineers continually evolve technology to improve the performance and life-cycle costs of batteries that store solar and wind energy. When designing a battery, engineers keep in mind the needs of the application, and use different substances to create current flow. They consider characteristics such as power output, ability to recharge, reliability, size, safety, heat generation, length of life cycle, abuse tolerance, cost and ability to be recycled. Isn't the power of engineering creativity amazing?

Learning Objectives

After this activity, students should be able to:

Describe the flow of electrical energy through a simple circuit.

Explain why a light bulb may take more than one battery to light up.

Explain the role of electrical engineers in the development of electricity sources and the products that use electricity.

Educational Standards

Each TeachEngineering lesson or activity is correlated to one or more K-12 science, technology, engineering or math (STEM) educational standards.

All 100,000+ K-12 STEM standards covered in TeachEngineering are collected, maintained and packaged by the Achievement Standards Network (ASN), a project of D2L (www.achievementstandards.org).

In the ASN, standards are hierarchically structured: first by source; e.g., by state; within source by type; e.g., science or mathematics; within type by subtype, then by grade, etc.

NGSS Performance Expectation

Click to view other curriculum aligned to this Performance Expectation

This activity focuses on the following Three Dimensional Learning aspects of NGSS:

Science & Engineering Practices

Disciplinary Core Ideas

Crosscutting Concepts

Make observations to produce data to serve as the basis for evidence for an explanation of a phenomenon or test a design solution.

Energy can be moved from place to place by moving objects or through sound, light, or electric currents. Energy is present whenever there are moving objects, sound, light, or heat. When objects collide, energy can be transferred from one object to another, thereby changing their motion. In such collisions, some energy is typically also transferred to the surrounding air; as a result, the air gets heated and sound is produced. Light also transfers energy from place to place. Energy can also be transferred from place to place by electric currents, which can then be used locally to produce motion, sound, heat, or light. The currents may have been produced to begin with by transforming the energy of motion into electrical energy.

Energy can be transferred in various ways and between objects.

Suggest an alignment not listed above

Materials List

To make a potato battery, each group needs:

3 copper pennies (or copper strips), one per potato

3 zinc nails; these are galvanized nails, available at hardware stores

5 insulated wires, 15-20 cm (6-8 inches) long, with alligator clips at the ends

1 low-current, light emitting diode (LED) clock (or LCD clock) requiring ~1.5 volts (or a small LED)

OR above materials can be purchased cumulatively in a kit, available online

For the entire class to share or one per team:

(optional) multimeter(s) or voltmeter(s); a multimeter measures current, voltage and resistance of a circuit; available at Radio Shack or other electronics stores or websites

Worksheets and Attachments
Visit [www.teachengineering.org/activities/view/cub_energy2_lesson04_activity2] to print or download.

Introduction/Motivation

What is electrical energy? From where does it come? Can you think of anything that needs electrical energy to work? How about lamps, music players, TVs and ovens? How do we get the power to run these devices? What role do electrical engineers play in improving our lives?

One place we can find electrical energy in our homes is at a wall outlet. So, how does electrical energy reach the wall outlet in our house? The energy comes from an electrical power plant, which usually makes electrical energy from burning fossil fuels, such as coal and oil. The heat energy from the burning fuel heats up water. When the water boils, it becomes steam, which flows through a pipe into a turbine (a wheel with blades). As the turbine spins from the steam, it turns a generator (a spinning magnet) that unbalances the charges in nearby atoms and produces a current of electricity. The electrical current flows through protected wires to our house.

How else can we power electrical appliances? That's right, from a battery. A battery works by providing electrons with a solution in which they can move around. Have you ever noticed that some batteries have a copper end that is positive (shown with a plus [+] sign) and another end that is negative (shown with a minus [-] sign)? Zinc is a metal that likes to give its electrons to copper. Usually, zinc just gives its electrons to copper and then the process stops. However, if you provide the electrons with a solution (called an electrolyte) to help them move to the copper, and you give the electrons a wire in which they can move from the copper back to the zinc, you can produce a circuit and a flowing path of electrical energy. (Note: Conventional current flows from positive to negative, so from the copper, through the wire, back to the zinc. The electrons actually flow negative to positive.)

A circuit is a complete path of electrical energy. This means that electrical energy or charge is produced or stored somewhere ( voltage) and has a path for the charge to flow (or current). Another part of a circuit is a resistance, such as a light bulb. Electrical engineers create circuits to help electrical energy perform work, such as lighting a room or keeping food cold. An appliance, light bulb or almost any device that uses electrical energy is a resistance. A resistance prevents or slows an electrical current or charge from moving. When electrical current flows through a source of resistance, it can be changed into light or heat or sound. Even though you cannot see it, the light bulb or appliance slows down the electrical charge.

Electrical engineers help develop the many modern products and appliances that require electrical energy. Electrical engineers also help create the technology used to generate the electrical energy in power plants in the first place. These engineers know a lot about circuits and they continually work to find better ways to store electrical charge and generate electrical current without using nonrenewable fossil fuels such as coal and oil. These electrical engineers are very important in almost everything we do! Essentially, electrical engineers create improvements for society and help save our planet for future generations. Today, we are going to be electrical engineers and learn more about how electrical energy works in a circuit. We are also going to look at generating electrical current from the energy stored in a potato! Do you think we can light a bulb with a potato? Let's try it!

Procedure

Background

How does a potato battery work? The copper (Cu) atoms attract electrons more than the zinc (Zn) atoms. If you place a strip of copper and a strip of zinc in contact with each other, many electrons pass from the zinc to the copper. As they concentrate on the copper, the electrons repel each other. When the force of repulsion between electrons and the force of attraction of electrons to the copper become equalized, the flow of electrons stops. Unfortunately it is not possible to take advantage of this behavior to produce electricity because the flow of charges stops almost immediately. On the other hand, if you bathe the two strips in a conductive solution, and connect them externally with a wire, the reactions between the electrodes and the solution continually furnish the circuit with charges. In this way, the process that produces the electrical energy continues and becomes useful. In a conductive solution, the charge is carried by ions that move through the solution. In the solid state, the ions are not able to move around freely. However, once they are dissolved in water, they become completely mobile. They can "swim" around in the water and thus can respond to an electric current from a battery. That current supplies electrons that cause positive ions to flow in one direction and negative ions to flow in the opposite direction. The ions carry electrical charge from one electrode to another, completing the electrical circuit.

For a conductive solution, use any electrolyte, whether it is an acid, base or salt solution. An electrolyte is a substance whose aqueous solution contains various ions and thus conducts electricity. Therefore, the more free ions a solution has, the better conductor it will be. Many fruits and vegetables contain juices rich in ions and are therefore good electrical conductors.

Like any battery, a potato battery has a limited life span. The electrodes undergo chemical reactions that block the flow of electricity. The electromotive force diminishes and the battery stops working. Usually, what happens is the production of hydrogen at the copper electrode and the zinc electrode acquires deposits of oxides that act as a barrier between the metal and the electrolyte. This is referred to as the electrodes being polarized. To achieve a longer life and higher voltages and current flows, it is necessary to use electrolytes better suited for the purpose. Commercial batteries, apart from their normal electrolyte, contain chemicals with an affinity for hydrogen, which combine with the hydrogen before it can polarize the electrodes.

Before the Activity

With the Students

1. Divide the class into teams of two or three students each. Hand out the materials.

2. Direct groups to carefully place the zinc nails and copper pennies into the potato. Make sure the two different metals do not touch each other in the potato (see Figure 1).

3. Connect one alligator clip to the end of the penny sticking out of the potato and another alligator clip to the end of the nail sticking out of the potato (see Figure 1).

Figure 1. Placement of the nail, penny and alligator clips.

1. (If you have a multimeter) Tell students that a multimeter is an instrument that measures current, voltage and resistance of a circuit, and is a tool (created by and) often used by engineers. Set the multimeter on a low "DC volts" scale for voltage and "DC milliamps" for current, so students can see the charge that one potato can produce. Expect the potato to produce just less than 1 volt. Encourage students to convert the decimal readout from the multimeter to a fraction (for example, 0.82 volts = 82/100 volts).

2. Have the students figure out how many potatoes they need to light their LED clock (or clock). For example, if their potato produces a voltage of 0.8 volts, then they may need two potatoes to power a 1.5 voltage LED.

3. Have students experiment to figure out how to connect two potatoes together. To connect two potatoes in series (to add more voltage), place a penny and nail into a second potato, and connect the wire from the zinc nail in the first potato to the copper penny in the second. Then, add a third wire to the zinc nail in the second potato. Always remember to connect the copper (positive) end of the potato (battery) to the zinc (negative) end of the next potato (see Figure 2).

Figure 2. Activity setup to create a potato battery to power an LED clock.

1. Expect two potatoes in series to be able to light an LED; however, you might need three. Show students how to connect the LEDs to the potato in the correct manner, that is, the positive end of the LED to the negative end of the potato battery (zinc nail) and the negative end of the LED to the positive end of the potato battery (copper penny).

2. Have students discuss how the potatoes provide the electrolyte (solution) for the chemical battery to work. Ask for suggestions of other foods we could try (for example, lemons, berries, apples).

3. Ask students to complete the worksheet either individually or in pairs. After they finish, have them compare answers with a peer or another pair, giving all students time to finish.

Vocabulary/Definitions

conductor: An object that allows the transfer of electrons.

current: The movement of electrons.

electrical energy: Energy produced through the movement of electrons (voltage X current).

electrolyte: A solution that conducts electricity.

energy: The ability to do work.

insulator: An object that inhibits the transfer of electrons.

resistance: Objects or substances that prevent the passage of a steady electric current.

voltage: The amount of energy produced.

Assessment

Pre-Activity Assessment

Brainstorming: In small groups, have students engage in open discussion. Remind them that no idea or suggestion is "silly." All ideas should be respectfully heard. Take an uncritical position, encourage wild ideas and discourage criticism of ideas. Ask students how many items they can think of that run on batteries. As a class, record their ideas on the board.

Quick Poll: Before the activity begins, ask the class a question and tally their responses on the board. Ask: Can we get electrical energy from a fruit or vegetable?

Activity Embedded Assessment

Worksheet /Pairs Check: Have students work individually or in pairs on the Make a Battery Worksheet. After they finish, have them compare answers with a peer or another pair, giving all students time to finish the worksheet.

Hypothesize: Ask each group what would happen if we added more potatoes in a row to our circuits? (Answer: Adding more potatoes in a row is the same as adding batteries in a row. The voltage of each piece of potato is added up. Thus, the voltage of our circuit would increase. On the other hand, the current of our circuit would not increase. Current is not dependent on how many potatoes but is related to the size of each potato individually.)

Post-Activity Assessment

Problem Solving: Present the class with the following math problems and ask students to calculate how many of each vegetable or fruit are needed to light the bulb.

If a lemon produces 1 Volt of energy, how many lemons would you need to light a 2 Volt light bulb? (Answer: 2)

If a potato produces 0.8 Volts of energy, how many potatoes would you need to light a 1.5 Volt light bulb? (Answer: 2)

If a potato produces 0.8 Volts of energy, how many potatoes would you need to light a 3 Volt digital clock? (Answer: 4)

If you have a lemon that produces 1 Volt of energy and an apple that produces 1 Volt of energy, can you light a 3 Volt clock? (Answer: No, you would need one more lemon or apple.)

Diagramming: Engineers must understand how circuits work in order to develop cool new technologies. Draw a picture of your potato battery. Label the battery (voltage) and the resistance (light bulb). Draw an arrow to show the current flow (from the copper end to the zinc end). List two cool products that an engineer could develop that run off a fruit battery.

Troubleshooting Tips

If the LED clock, light or small light bulbs do not work, check the setup of the potato battery. Perhaps the ends are not all connected from negative to positive, or perhaps there is not enough potato voltage. Check the voltage of the potato using a multimeter or voltmeter. Another possibility is having enough voltage, but not enough current to light the bulb, which is why it is recommended to use only very low-volt LED clocks or bulbs. Also, try using more potatoes (i.e., 5 potato halves) to strengthen conductivity. Try different LED colors (for example, the blue LED may work better than the red).

Lemons and oranges also work well for this activity. They work best if you first roll them on a table top, which breaks down the cells inside so more juice flows through the fruit (current).

Some people have more conduction success using copper strips instead of copper pennies (can also wrap the pennies in copper ribbon).

Soaking the potatoes in Gatorade overnight can make them more conductive.

Activity Extensions

At activity end, before students disassemble their potato batteries, it is fun to have the entire class connect their fruit batteries in series, making "a serious tater circle."

Have students try the activity again using different fruits or vegetables! Many fruits and vegetables work, such as lemons, limes, apples and carrots. Have students compare and contrast the performance of different fruits and vegetables.

Have students complete the activity again using an electrolyte solution, such as salt water or vinegar. Have them compare and contrast the performance of different electrolyte solutions.

To add a math component, have students use the multimeter to compare the flow of electricity for several different fruits as well as to the total amount of fruits used. Ask them to graph the results and hypothesize what is happening.

Activity Scaling

Have more advanced students experiment with parallel and series configurations using different numbers of potatoes.

References

Dictionary.com. Lexico Publishing Group, LLC. Accessed September 28, 2005. (Source of some vocabulary definitions, with some adaptation) http://www.dictionary.com

Phillips, W.D. Chapter 2P: Using a Multimeter. Design Electronics (online textbook) DOCTRONICS Educational Publishing, UK. Accessed September 28, 2005. (Good design, technology and electronics resources.) http://www.doctronics.co.uk/meter.htm

Copyright © 2005 by Regents of the University of Colorado

Contributors Sharon D. Perez-Suarez; Jeff Lyng; Malinda Schaefer Zarske; Denise W. Carlson; Janet Yowell

Supporting Program Integrated Teaching and Learning Program, College of Engineering, University of Colorado Boulder

Acknowledgements

The contents of this digital library curriculum were developed under grants from the Fund for the Improvement of Postsecondary Education (FIPSE), U.S. Department of Education, and the National Science Foundation (GK-12 grant no. 0338326). However, these contents do not necessarily represent the policies of the Department of Education or National Science Foundation, and you should not assume endorsement by the federal government.

Last modified: July 9, 2020

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Students use potatoes to light an LED clock (or light bulb) as they learn how a battery works in a simple circuit and how chemical energy changes to electrical energy. As they learn more about electrical energy, they better understand the concepts of voltage, current and resistance.

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I really enjoyed this lesson because it allows the students to create something on their own all the while flinging marshmallows all over the place. It could also be a good competition to see whole could fling them the farthest.

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Posted on by ASEE

(Lesson Courtesy COSI Columbus - The Center for Science and Industry). Level: Grades 4 - 8. Time required: 30 to 50 minutes. Click HERE for PDF of activity. Click HERE for version developed by Ohio State University engineering graduate students and Maize Elementary teachers

Overview

This simple catapult activity for students in grades 4 - 8 teaches them how energy is transferred when a plastic spoon is pulled back, then released, rocketing its payload - a single marshmallow.

Background

What's going on? The plastic spoon has an inherent elasticity, which means it will return to its original shape after being deformed. Rubber bands and other elastic objects also have this property. When the spoon is deformed, the force used to cause that deformation is "stored" in the spoon as elastic potential energy. When the spoon is released, the elastic potential energy changes to kinetic energy as the spoon returns to its original shape, carrying the marshmallow along with it. The marshmallow continues to move after the spoon has stopped due to its inertia.

Catapult Information

(from the Museum of Ancient Inventions, Smith College)

The catapult was an ancient siege machine that could hurl heavy objects or shoot arrows with great force and for considerable distances. Some catapults could throw stones weighing as much as 350 pounds for distances greater than 300 feet.

The Greek Dionysius the Elder of Syracuse, who was looking to develop a new type of weapon, invented the catapult about 400 BCE. Thereafter, it became a key weapon in warfare and remained so up through mediaeval times. Two major catapults evolved from Dionysius's invention: the double-armed machine, or ballista, used for shooting arrows, and the single-armed catapult designed for hurling large objects. Although the Romans added wheels to both types of catapult for maneuverability, very little in the design of the machine changed.The reconstruction shown here is of a single-armed stone-hurling catapult, approximately two feet long and one-and-a-half feet tall. Its hurling arm is driven by a cocked, winch-pulled cord.

Standards (Ohio)

Physical Science: 1.6, 3.3, 3.4, 7.2, 7.4

Vocabulary

elasticity, potential energy, kinetic energy, deflection angle

Materials

Plastic spoon

1-2 bags of miniature marshmallows

marking pens

tape measure or meter stick

masking tape

protractor

safety goggles

Procedure
Instruction for teachers:
Set up the classroom so that you have at least 20 feet of open space in front of the launching area for a landing area. Have students put on goggles, then align teams of 3-4 students along one side of a set of long tables or a counter so the catapults will be aimed across the room.

Distribute to each group safety goggles, spoons, marshmallows, protractors, and lengths of masking tape.
Instructions for students:
1. Prepare your catapult by taping a spoon firmly against the edge of a table, perpendicular to the tabletop with the bowl of the spoon facing toward the table.

2. Mark your marshmallows for identification with a pen, using your group initials.

3. Test the setup of your catapult and marshmallow: Hold the marshmallow in the bowl of the spoon. Use your thumb to help anchor the spoon handle against the table.

4. Practice launch: Keeping the end of the spoon handle against the table, launching the marshmallow across the room. (Don't point it at anyone!)

5. Experiment with pulling the spoon back farther to change the angle - what are the results?

Now, determine the best deflection angle - how far you pull back the spoon - to launch the marshmallow the farthest possible distance. Decide how much to deflect the spoon, using a protractor to measure the angle between the spoon and the table. Record the measurements of your deflection angle on a sheet of paper, then launch your marshmallow and measure the distance it travels. Repeat this two more times and compute the average of the three.

6. Now, change the deflection angle of the catapult and repeat. Record the average distance for three separate different catapult angles. Record your results. What angle between the spoon and table launches the marshmallow the farthest?

7. Based on your data, predict the optimum deflection angle.

8. Hold a class contest to find out who can make a marshmallow fly the farthest.

Extensions

Ask the class what would happen if they changed the weight/size of the marshmallow - and how could they do that? Which other techniques could makes the marshmallow go farther? Higher?

Spoons may be made of several different types of plastic. Bring in other plastic spoons and try this experiment. Compare and contrast the results. Look up the properties of the different types of plastic and relate these properties to the results.

For homework, challenge students to come up with their own catapult design - still using the marshmallow load - then allow them to construct, test, and demonstrate their models in class the next day. What innovative solutions did each group devise? Have students evaluate their results and those of their classmates.

Assign students to research the history of catapults. When were they used, and for what purposes?

Resources

More ancient inventions at Smith College's online Museum of Ancient Inventions
http://www.middle-ages.org.uk/catapults.htm http://www.medieval-castle-siege-weapons.com/medieval-catapults.html
Filed under: Class Activities, Grades 6-8, Grades K-5, Grades K-5, Lesson Plans

Tags: catapult, Class Activities, forces and motion, Fun & Games, Grades 4 - 8, Grades K-5, Newton's Laws, Physical Science, Physics, trebuchet

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eGFI - For Teachers " Activity: Catapult Marshmallow Launch

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Posted on by ASEE (Lesson Courtesy COSI Columbus - The Center for Science and Industry). Level: Grades 4 - 8. Time required: 30 to 50 minutes. Click HERE for PDF of activity.

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I love this lesson plan because it integrates literacy within a STEM activity because it is all based on a Dr. Suess book. This lesson fosters 21st Century Skills such as collaboration, critical thinking and flexibility (the substance is constantly changing). I loved making this as a kid.
-Jackie Flick

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Have you ever read Dr. Seuss? I'm pretty sure everyone with kids has! Did you know that Dr. Seuss created the name of one of our favourite science experiments? Yup, Oobleck got it's name from Bartholomew and the Oobleck, a story about a bored king with a team of magicians at his disposal. You can imagine the chaos! So we created our own Bartholomew and the Oobleck inspired STEM activity to recreate the story. It was marvelously messy hands on STEM learning!

Bartholomew and the Oobleck - Dr. Seuss Inspired Learning
Disclaimer: This post contains affiliate links
Oobleck - non-Newtonian Fluid

We love a great science experiment, especially when it is a rule breaker like Oobleck. Known as a non-Newtonian fluid, oobleck breaks Newton's Laws of Fluid Dynamics. To understand this law think about how liquids normally behave. Water flows smoothly and freely, but mix in a bit of dirt to create mud and it slows down. This is because the dynamics (behaviours) of fluids are affected by their viscosity and density.

Want to learn more about the science of oobleck? Check out this article on our Colour Changing Oobleck or our Glow in the Dark Oobleck Activity for lots of great scientific details.

Dr. Seuss' Bartholomew and the Oobleck

As much as we love oobleck, we had never read the book that inspired the name. So I set out to get the book and add it to our collection. It turns out this was a little harder than I anticipated. See the book was published in 1949 (and won the Caldecott Honor-winning picture book 1950). Since this book is quite old, it wasn't available in any of my local bookstores. In the end I ordered it online. It was definitely worth it (even though I do prefer to visit bookstores in person!).

The book is about a bored king, King Derwin of Didd. Why is he so bored? He is bored by the weather. Sun, rain, fog and snow are just much too boring for him. So he tasks his team of royal magicians to create a new weather to make him happy.

The result is this sticky, gloppy creation that rains from the skies and creates complete havoc for the entire village.

In the end the king learns a valuable lesson about the power of words and we are introduced to the wonders of oobleck!

After reading the book we decided it would make amazing inspiration for a STEM activity.

Bartholomew and the Oobleck STEM Activity Supplies

To do this STEM activity you will need items you likely already have laying around the house.

Bartholomew and the Oobleck - it makes sense to have the book so you can do this as a full unit study!
Cornstarch
Water
Green food colouring
Bowl
Spoon
Lego - plates, blocks and minifigs
Some type of mesh (you could even build a grid from Lego pieces if you prefer)
Large, shallow edged dish
Easy to clean space

Bartholomew and the Oobleck Inspired STEM Project

After reading the book together, we were ready for our oobleck STEM activity.

First up we needed to build our "village". We built two walls with 2x bricks on a baseplate. Then we attached our mesh to the top. The weight of the oobleck did cause our walls to tip in. So we supported the walls with a few extra bricks at the bottom. Next time I would encourage the kids to come up with other ways to make the walls sturdier, such as adding beams or a grid to the top. This worked, but it wasn't the most stable construction with the weight of the oobleck added to the top.

Next we added our villagers! Don't they look like happy little villagers just going about their day? Except of course the oobleck raining down on their heads!

Once it was all built we carefully placed it all in a large shallow lipped tray to catch all the mess. Then we placed it on a table in an easy to clean up area. Oobleck is messy fun, so always plan ahead for easy clean up.

Now it was time to mix up our oobleck! Oobleck is soooo easy to make. Simply take 2 cups of cornstarch and 1 cup of water and add to a large bowl. Since the oobleck was green in Bartholomew and the Oobleck, we coloured our water green first before mixing it with the cornstarch.

Almost immediately you will start to see that non-Newtonian fluid dynamic as you try and mix it all together. The trick is to move slowly. The more pressure you place on the oobleck the harder it will get.

Once mixed it was time to reenact the book!

Oobleck, King Derwin and the Village of Didd

Before we started my son insisted on adding a minifig to represent King Derwin. He chose a knight and placed it at the very top, where he could see the chaos he unleashed on the people.

Now it was time for the magicians to unleash their magic goop - Oobleck!

We carefully scooped up the oobleck and added it to the top of our mesh. We watched as it would clump, then run, then clump and run. It was clump as it hit the mesh, then liquify and run through the mesh, but then it would clump again as it hit other bits of oobleck falling down. As it hit our village and our innocent villagers it would once again clump. It was fascinating to watch!

Now if your children have never used oobleck, you should spend some time letting them explore the properties of oobleck with their hands. It is such a cool substance that turns solid under pressure and liquefies when you remove the pressure. Having an understanding of those properties before starting this experiment will help them understand why it behaves in such a strange way as it rains down on their village.

The gloopy oobleck made for some really funny moments. Oobleck hat anyone?

CHECK OUT THE OOBLECK IN ACTION AS IT RAINS DOWN ON OUR VILLAGE!

MORE GREAT OOBLECK STUDIES

Oobleck is a fantastic science study. Check out some of our other oobleck projects.
Colour Changing Oobleck (acid-base study) Halloween Oobleck Game Glow in the Dark Oobleck Introduction to Oobleck
Have fun exploring this non-Newtonian fluid rule breaker in your science lessons!

MORE LEGO STEM ACTIVITIES

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Bartholomew and the Oobleck STEM Activity for elementary

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Have you ever read Dr. Seuss? I'm pretty sure everyone with kids has! Did you know that Dr. Seuss created the name of one of our favourite science experiments? Yup, Oobleck got it's name from Bartholomew and the Oobleck , a story about a bored king with a team of magicians at his disposal.

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The ocean survival lesson is something I would enjoy teaching due to the emphasis on critical thinking skills and having a worksheet/any way to keep track of their progress while their working on something that could be distracted would be a great way to learn.

-Austin Miller

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Students would have so much fun creating this Ooblek. I would integrate this into a science lesson in my classroom because it has an interesting twist on states of matter. Is it a solid? A liquid? Students would also enjoy picking their color that they want their Ooblek to be! -Victoria Malpica

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Have you ever read Dr. Seuss? I'm pretty sure everyone with kids has! Did you know that Dr. Seuss created the name of one of our favourite science experiments? Yup, Oobleck got it's name from Bartholomew and the Oobleck, a story about a bored king with a team of magicians at his disposal. You can imagine the chaos! So we created our own Bartholomew and the Oobleck inspired STEM activity to recreate the story. It was marvelously messy hands on STEM learning!

Bartholomew and the Oobleck - Dr. Seuss Inspired Learning
Disclaimer: This post contains affiliate links
Oobleck - non-Newtonian Fluid

We love a great science experiment, especially when it is a rule breaker like Oobleck. Known as a non-Newtonian fluid, oobleck breaks Newton's Laws of Fluid Dynamics. To understand this law think about how liquids normally behave. Water flows smoothly and freely, but mix in a bit of dirt to create mud and it slows down. This is because the dynamics (behaviours) of fluids are affected by their viscosity and density.

Want to learn more about the science of oobleck? Check out this article on our Colour Changing Oobleck or our Glow in the Dark Oobleck Activity for lots of great scientific details.

Dr. Seuss' Bartholomew and the Oobleck

As much as we love oobleck, we had never read the book that inspired the name. So I set out to get the book and add it to our collection. It turns out this was a little harder than I anticipated. See the book was published in 1949 (and won the Caldecott Honor-winning picture book 1950). Since this book is quite old, it wasn't available in any of my local bookstores. In the end I ordered it online. It was definitely worth it (even though I do prefer to visit bookstores in person!).

The book is about a bored king, King Derwin of Didd. Why is he so bored? He is bored by the weather. Sun, rain, fog and snow are just much too boring for him. So he tasks his team of royal magicians to create a new weather to make him happy.

The result is this sticky, gloppy creation that rains from the skies and creates complete havoc for the entire village.

In the end the king learns a valuable lesson about the power of words and we are introduced to the wonders of oobleck!

After reading the book we decided it would make amazing inspiration for a STEM activity.

Bartholomew and the Oobleck STEM Activity Supplies

To do this STEM activity you will need items you likely already have laying around the house.

Bartholomew and the Oobleck - it makes sense to have the book so you can do this as a full unit study!
Cornstarch
Water
Green food colouring
Bowl
Spoon
Lego - plates, blocks and minifigs
Some type of mesh (you could even build a grid from Lego pieces if you prefer)
Large, shallow edged dish
Easy to clean space

Bartholomew and the Oobleck Inspired STEM Project

After reading the book together, we were ready for our oobleck STEM activity.

First up we needed to build our "village". We built two walls with 2x bricks on a baseplate. Then we attached our mesh to the top. The weight of the oobleck did cause our walls to tip in. So we supported the walls with a few extra bricks at the bottom. Next time I would encourage the kids to come up with other ways to make the walls sturdier, such as adding beams or a grid to the top. This worked, but it wasn't the most stable construction with the weight of the oobleck added to the top.

Next we added our villagers! Don't they look like happy little villagers just going about their day? Except of course the oobleck raining down on their heads!

Once it was all built we carefully placed it all in a large shallow lipped tray to catch all the mess. Then we placed it on a table in an easy to clean up area. Oobleck is messy fun, so always plan ahead for easy clean up.

Now it was time to mix up our oobleck! Oobleck is soooo easy to make. Simply take 2 cups of cornstarch and 1 cup of water and add to a large bowl. Since the oobleck was green in Bartholomew and the Oobleck, we coloured our water green first before mixing it with the cornstarch.

Almost immediately you will start to see that non-Newtonian fluid dynamic as you try and mix it all together. The trick is to move slowly. The more pressure you place on the oobleck the harder it will get.

Once mixed it was time to reenact the book!

Oobleck, King Derwin and the Village of Didd

Before we started my son insisted on adding a minifig to represent King Derwin. He chose a knight and placed it at the very top, where he could see the chaos he unleashed on the people.

Now it was time for the magicians to unleash their magic goop - Oobleck!

We carefully scooped up the oobleck and added it to the top of our mesh. We watched as it would clump, then run, then clump and run. It was clump as it hit the mesh, then liquify and run through the mesh, but then it would clump again as it hit other bits of oobleck falling down. As it hit our village and our innocent villagers it would once again clump. It was fascinating to watch!

Now if your children have never used oobleck, you should spend some time letting them explore the properties of oobleck with their hands. It is such a cool substance that turns solid under pressure and liquefies when you remove the pressure. Having an understanding of those properties before starting this experiment will help them understand why it behaves in such a strange way as it rains down on their village.

The gloopy oobleck made for some really funny moments. Oobleck hat anyone?

CHECK OUT THE OOBLECK IN ACTION AS IT RAINS DOWN ON OUR VILLAGE!

MORE GREAT OOBLECK STUDIES

Oobleck is a fantastic science study. Check out some of our other oobleck projects.
Colour Changing Oobleck (acid-base study) Halloween Oobleck Game Glow in the Dark Oobleck Introduction to Oobleck
Have fun exploring this non-Newtonian fluid rule breaker in your science lessons!

MORE LEGO STEM ACTIVITIES

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Bartholomew and the Oobleck STEM Activity for elementary

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Have you ever read Dr. Seuss? I'm pretty sure everyone with kids has! Did you know that Dr. Seuss created the name of one of our favourite science experiments? Yup, Oobleck got it's name from Bartholomew and the Oobleck , a story about a bored king with a team of magicians at his disposal.

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I chose this lesson because this lesson would be so much fun to do. It is a really good way to teach about energy.
-Courtney Drennen

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Posted on by ASEE

(Lesson Courtesy COSI Columbus - The Center for Science and Industry). Level: Grades 4 - 8. Time required: 30 to 50 minutes. Click HERE for PDF of activity. Click HERE for version developed by Ohio State University engineering graduate students and Maize Elementary teachers

Overview

This simple catapult activity for students in grades 4 - 8 teaches them how energy is transferred when a plastic spoon is pulled back, then released, rocketing its payload - a single marshmallow.

Background

What's going on? The plastic spoon has an inherent elasticity, which means it will return to its original shape after being deformed. Rubber bands and other elastic objects also have this property. When the spoon is deformed, the force used to cause that deformation is "stored" in the spoon as elastic potential energy. When the spoon is released, the elastic potential energy changes to kinetic energy as the spoon returns to its original shape, carrying the marshmallow along with it. The marshmallow continues to move after the spoon has stopped due to its inertia.

Catapult Information

(from the Museum of Ancient Inventions, Smith College)

The catapult was an ancient siege machine that could hurl heavy objects or shoot arrows with great force and for considerable distances. Some catapults could throw stones weighing as much as 350 pounds for distances greater than 300 feet.

The Greek Dionysius the Elder of Syracuse, who was looking to develop a new type of weapon, invented the catapult about 400 BCE. Thereafter, it became a key weapon in warfare and remained so up through mediaeval times. Two major catapults evolved from Dionysius's invention: the double-armed machine, or ballista, used for shooting arrows, and the single-armed catapult designed for hurling large objects. Although the Romans added wheels to both types of catapult for maneuverability, very little in the design of the machine changed.The reconstruction shown here is of a single-armed stone-hurling catapult, approximately two feet long and one-and-a-half feet tall. Its hurling arm is driven by a cocked, winch-pulled cord.

Standards (Ohio)

Physical Science: 1.6, 3.3, 3.4, 7.2, 7.4

Vocabulary

elasticity, potential energy, kinetic energy, deflection angle

Materials

Plastic spoon

1-2 bags of miniature marshmallows

marking pens

tape measure or meter stick

masking tape

protractor

safety goggles

Procedure
Instruction for teachers:
Set up the classroom so that you have at least 20 feet of open space in front of the launching area for a landing area. Have students put on goggles, then align teams of 3-4 students along one side of a set of long tables or a counter so the catapults will be aimed across the room.

Distribute to each group safety goggles, spoons, marshmallows, protractors, and lengths of masking tape.
Instructions for students:
1. Prepare your catapult by taping a spoon firmly against the edge of a table, perpendicular to the tabletop with the bowl of the spoon facing toward the table.

2. Mark your marshmallows for identification with a pen, using your group initials.

3. Test the setup of your catapult and marshmallow: Hold the marshmallow in the bowl of the spoon. Use your thumb to help anchor the spoon handle against the table.

4. Practice launch: Keeping the end of the spoon handle against the table, launching the marshmallow across the room. (Don't point it at anyone!)

5. Experiment with pulling the spoon back farther to change the angle - what are the results?

Now, determine the best deflection angle - how far you pull back the spoon - to launch the marshmallow the farthest possible distance. Decide how much to deflect the spoon, using a protractor to measure the angle between the spoon and the table. Record the measurements of your deflection angle on a sheet of paper, then launch your marshmallow and measure the distance it travels. Repeat this two more times and compute the average of the three.

6. Now, change the deflection angle of the catapult and repeat. Record the average distance for three separate different catapult angles. Record your results. What angle between the spoon and table launches the marshmallow the farthest?

7. Based on your data, predict the optimum deflection angle.

8. Hold a class contest to find out who can make a marshmallow fly the farthest.

Extensions

Ask the class what would happen if they changed the weight/size of the marshmallow - and how could they do that? Which other techniques could makes the marshmallow go farther? Higher?

Spoons may be made of several different types of plastic. Bring in other plastic spoons and try this experiment. Compare and contrast the results. Look up the properties of the different types of plastic and relate these properties to the results.

For homework, challenge students to come up with their own catapult design - still using the marshmallow load - then allow them to construct, test, and demonstrate their models in class the next day. What innovative solutions did each group devise? Have students evaluate their results and those of their classmates.

Assign students to research the history of catapults. When were they used, and for what purposes?

Resources

More ancient inventions at Smith College's online Museum of Ancient Inventions
http://www.middle-ages.org.uk/catapults.htm http://www.medieval-castle-siege-weapons.com/medieval-catapults.html
Filed under: Class Activities, Grades 6-8, Grades K-5, Grades K-5, Lesson Plans

Tags: catapult, Class Activities, forces and motion, Fun & Games, Grades 4 - 8, Grades K-5, Newton's Laws, Physical Science, Physics, trebuchet

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eGFI - For Teachers " Activity: Catapult Marshmallow Launch

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Posted on by ASEE (Lesson Courtesy COSI Columbus - The Center for Science and Industry). Level: Grades 4 - 8. Time required: 30 to 50 minutes. Click HERE for PDF of activity.

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I chose the marshmallow catapults because I think that shooting catapults would be so fun for kids. Kids love using food in class especially if they can fling it! I think that even though it is fun it also hits on math and science along with many standards!
-Alexis Cancila

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Posted on by ASEE

(Lesson Courtesy COSI Columbus - The Center for Science and Industry). Level: Grades 4 - 8. Time required: 30 to 50 minutes. Click HERE for PDF of activity. Click HERE for version developed by Ohio State University engineering graduate students and Maize Elementary teachers

Overview

This simple catapult activity for students in grades 4 - 8 teaches them how energy is transferred when a plastic spoon is pulled back, then released, rocketing its payload - a single marshmallow.

Background

What's going on? The plastic spoon has an inherent elasticity, which means it will return to its original shape after being deformed. Rubber bands and other elastic objects also have this property. When the spoon is deformed, the force used to cause that deformation is "stored" in the spoon as elastic potential energy. When the spoon is released, the elastic potential energy changes to kinetic energy as the spoon returns to its original shape, carrying the marshmallow along with it. The marshmallow continues to move after the spoon has stopped due to its inertia.

Catapult Information

(from the Museum of Ancient Inventions, Smith College)

The catapult was an ancient siege machine that could hurl heavy objects or shoot arrows with great force and for considerable distances. Some catapults could throw stones weighing as much as 350 pounds for distances greater than 300 feet.

The Greek Dionysius the Elder of Syracuse, who was looking to develop a new type of weapon, invented the catapult about 400 BCE. Thereafter, it became a key weapon in warfare and remained so up through mediaeval times. Two major catapults evolved from Dionysius's invention: the double-armed machine, or ballista, used for shooting arrows, and the single-armed catapult designed for hurling large objects. Although the Romans added wheels to both types of catapult for maneuverability, very little in the design of the machine changed.The reconstruction shown here is of a single-armed stone-hurling catapult, approximately two feet long and one-and-a-half feet tall. Its hurling arm is driven by a cocked, winch-pulled cord.

Standards (Ohio)

Physical Science: 1.6, 3.3, 3.4, 7.2, 7.4

Vocabulary

elasticity, potential energy, kinetic energy, deflection angle

Materials

Plastic spoon

1-2 bags of miniature marshmallows

marking pens

tape measure or meter stick

masking tape

protractor

safety goggles

Procedure
Instruction for teachers:
Set up the classroom so that you have at least 20 feet of open space in front of the launching area for a landing area. Have students put on goggles, then align teams of 3-4 students along one side of a set of long tables or a counter so the catapults will be aimed across the room.

Distribute to each group safety goggles, spoons, marshmallows, protractors, and lengths of masking tape.
Instructions for students:
1. Prepare your catapult by taping a spoon firmly against the edge of a table, perpendicular to the tabletop with the bowl of the spoon facing toward the table.

2. Mark your marshmallows for identification with a pen, using your group initials.

3. Test the setup of your catapult and marshmallow: Hold the marshmallow in the bowl of the spoon. Use your thumb to help anchor the spoon handle against the table.

4. Practice launch: Keeping the end of the spoon handle against the table, launching the marshmallow across the room. (Don't point it at anyone!)

5. Experiment with pulling the spoon back farther to change the angle - what are the results?

Now, determine the best deflection angle - how far you pull back the spoon - to launch the marshmallow the farthest possible distance. Decide how much to deflect the spoon, using a protractor to measure the angle between the spoon and the table. Record the measurements of your deflection angle on a sheet of paper, then launch your marshmallow and measure the distance it travels. Repeat this two more times and compute the average of the three.

6. Now, change the deflection angle of the catapult and repeat. Record the average distance for three separate different catapult angles. Record your results. What angle between the spoon and table launches the marshmallow the farthest?

7. Based on your data, predict the optimum deflection angle.

8. Hold a class contest to find out who can make a marshmallow fly the farthest.

Extensions

Ask the class what would happen if they changed the weight/size of the marshmallow - and how could they do that? Which other techniques could makes the marshmallow go farther? Higher?

Spoons may be made of several different types of plastic. Bring in other plastic spoons and try this experiment. Compare and contrast the results. Look up the properties of the different types of plastic and relate these properties to the results.

For homework, challenge students to come up with their own catapult design - still using the marshmallow load - then allow them to construct, test, and demonstrate their models in class the next day. What innovative solutions did each group devise? Have students evaluate their results and those of their classmates.

Assign students to research the history of catapults. When were they used, and for what purposes?

Resources

More ancient inventions at Smith College's online Museum of Ancient Inventions
http://www.middle-ages.org.uk/catapults.htm http://www.medieval-castle-siege-weapons.com/medieval-catapults.html
Filed under: Class Activities, Grades 6-8, Grades K-5, Grades K-5, Lesson Plans

Tags: catapult, Class Activities, forces and motion, Fun & Games, Grades 4 - 8, Grades K-5, Newton's Laws, Physical Science, Physics, trebuchet

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eGFI - For Teachers " Activity: Catapult Marshmallow Launch

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Posted on by ASEE (Lesson Courtesy COSI Columbus - The Center for Science and Industry). Level: Grades 4 - 8. Time required: 30 to 50 minutes. Click HERE for PDF of activity.

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I chose this lesson because I think it would be a really fun way for the students to learn math, science, and engineering. It also only needs easy to get items, most of which will already be in the classroom.
~Sara Flood

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Posted on by ASEE

(Lesson Courtesy COSI Columbus - The Center for Science and Industry). Level: Grades 4 - 8. Time required: 30 to 50 minutes. Click HERE for PDF of activity. Click HERE for version developed by Ohio State University engineering graduate students and Maize Elementary teachers

Overview

This simple catapult activity for students in grades 4 - 8 teaches them how energy is transferred when a plastic spoon is pulled back, then released, rocketing its payload - a single marshmallow.

Background

What's going on? The plastic spoon has an inherent elasticity, which means it will return to its original shape after being deformed. Rubber bands and other elastic objects also have this property. When the spoon is deformed, the force used to cause that deformation is "stored" in the spoon as elastic potential energy. When the spoon is released, the elastic potential energy changes to kinetic energy as the spoon returns to its original shape, carrying the marshmallow along with it. The marshmallow continues to move after the spoon has stopped due to its inertia.

Catapult Information

(from the Museum of Ancient Inventions, Smith College)

The catapult was an ancient siege machine that could hurl heavy objects or shoot arrows with great force and for considerable distances. Some catapults could throw stones weighing as much as 350 pounds for distances greater than 300 feet.

The Greek Dionysius the Elder of Syracuse, who was looking to develop a new type of weapon, invented the catapult about 400 BCE. Thereafter, it became a key weapon in warfare and remained so up through mediaeval times. Two major catapults evolved from Dionysius's invention: the double-armed machine, or ballista, used for shooting arrows, and the single-armed catapult designed for hurling large objects. Although the Romans added wheels to both types of catapult for maneuverability, very little in the design of the machine changed.The reconstruction shown here is of a single-armed stone-hurling catapult, approximately two feet long and one-and-a-half feet tall. Its hurling arm is driven by a cocked, winch-pulled cord.

Standards (Ohio)

Physical Science: 1.6, 3.3, 3.4, 7.2, 7.4

Vocabulary

elasticity, potential energy, kinetic energy, deflection angle

Materials

Plastic spoon

1-2 bags of miniature marshmallows

marking pens

tape measure or meter stick

masking tape

protractor

safety goggles

Procedure
Instruction for teachers:
Set up the classroom so that you have at least 20 feet of open space in front of the launching area for a landing area. Have students put on goggles, then align teams of 3-4 students along one side of a set of long tables or a counter so the catapults will be aimed across the room.

Distribute to each group safety goggles, spoons, marshmallows, protractors, and lengths of masking tape.
Instructions for students:
1. Prepare your catapult by taping a spoon firmly against the edge of a table, perpendicular to the tabletop with the bowl of the spoon facing toward the table.

2. Mark your marshmallows for identification with a pen, using your group initials.

3. Test the setup of your catapult and marshmallow: Hold the marshmallow in the bowl of the spoon. Use your thumb to help anchor the spoon handle against the table.

4. Practice launch: Keeping the end of the spoon handle against the table, launching the marshmallow across the room. (Don't point it at anyone!)

5. Experiment with pulling the spoon back farther to change the angle - what are the results?

Now, determine the best deflection angle - how far you pull back the spoon - to launch the marshmallow the farthest possible distance. Decide how much to deflect the spoon, using a protractor to measure the angle between the spoon and the table. Record the measurements of your deflection angle on a sheet of paper, then launch your marshmallow and measure the distance it travels. Repeat this two more times and compute the average of the three.

6. Now, change the deflection angle of the catapult and repeat. Record the average distance for three separate different catapult angles. Record your results. What angle between the spoon and table launches the marshmallow the farthest?

7. Based on your data, predict the optimum deflection angle.

8. Hold a class contest to find out who can make a marshmallow fly the farthest.

Extensions

Ask the class what would happen if they changed the weight/size of the marshmallow - and how could they do that? Which other techniques could makes the marshmallow go farther? Higher?

Spoons may be made of several different types of plastic. Bring in other plastic spoons and try this experiment. Compare and contrast the results. Look up the properties of the different types of plastic and relate these properties to the results.

For homework, challenge students to come up with their own catapult design - still using the marshmallow load - then allow them to construct, test, and demonstrate their models in class the next day. What innovative solutions did each group devise? Have students evaluate their results and those of their classmates.

Assign students to research the history of catapults. When were they used, and for what purposes?

Resources

More ancient inventions at Smith College's online Museum of Ancient Inventions
http://www.middle-ages.org.uk/catapults.htm http://www.medieval-castle-siege-weapons.com/medieval-catapults.html
Filed under: Class Activities, Grades 6-8, Grades K-5, Grades K-5, Lesson Plans

Tags: catapult, Class Activities, forces and motion, Fun & Games, Grades 4 - 8, Grades K-5, Newton's Laws, Physical Science, Physics, trebuchet

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eGFI - For Teachers " Activity: Catapult Marshmallow Launch

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Posted on by ASEE (Lesson Courtesy COSI Columbus - The Center for Science and Industry). Level: Grades 4 - 8. Time required: 30 to 50 minutes. Click HERE for PDF of activity.

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This lesson I had a personal enjoyment with to do how interactive and frankly how silly gross it is. However, the real key to this lesson that I enjoyed is that students can form their own  shapes and figure along with colors and creative decisions.
-Austin Miller

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Make plastic from milk? It seems like some sort of lactose intolerant horror story, but it's actually a really cool science process. Create your own toys, beads, jewelry, and more, with ingredients you have right now in your kitchen. It's so easy and super cool!

Turn Milk Into Plastic Toys!
Disclaimer: This article may contain commission or affiliate links. As an Amazon Associate I earn from qualifying purchases.
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Also known as casein plastic, this process has been used for over 100 years and is the way they used to make plastics before 1945 when synthetic plastics were introduced. Even royalty wore jewelry made from milk plastic many years ago. How cool is that?

With this simple process you can make toys, beads, jewelry, decorative pieces and more. This is a great, budget friendly experiment, with spectacular results that will have your students pumped with excitement for science!

A stove top or microwave to warm the milk
Milk (we used 2%, lower fat content is better)
White Vinegar or Lemon Juice
Bowl
Spoon
Strainer (or can create your own using cheese cloth or similar)
Paper towel
Molds (we loved using our Lego minifigures and Dinosaur molds) or other tools for shaping.

Time: 30 to 90 minutes for the experiment, then 2 days for drying. Add in a little extra time for painting once dry!

Measure out 1 cup of milk (you can also use chocolate milk and the end result smells amazing!), this makes about 4 minifigures or 4 dinosaurs. Heat on the stove top in a pot or in the microwave in a heat resistant bowl. You want it to just start steaming. Remove from the heat. Add 4 tsp of vinegar or lemon juice and stir gently.

The amount of vinegar is not exact. We used 4 tbsp by accident and it was fine, just made for a more intense vinegar smell!

You will notice that it immediately begins to curdle. You're making curds and whey!

Stir gently for approximately one minute for the full reaction to finish and all the curds to form. Don't stir aggressively. Be gentle.

Strain off the whey using a strainer or you can use cheese cloth (or similar). Let drip for a few minutes until most of the liquid has drained off. Gently smoosh the curds around in the strainer if needed.

Now remove the curds and place them on a few layers of paper towel. Carefully pat and squish to remove more liquid. You may need to replace the paper towel and repeat a few times. The goal is to remove as much liquid as possible.

You will notice it is kind of crumbly and squishy, but you can smoosh and shape it.

Now you can put it in your molds at this point but we discovered that if you put the curds in a jar or bowl, soaking in vinegar for an hour, you will get a much smoother final product. Plus they are more white if you do this extra step. If you do the extra vinegar soak, once the hour is up, repeat the straining, and paper towel drying process again. This time you will notice it is smoother in texture and no longer crumbly.

During the vinegar soak you can add some food colouring if you want. Just put a few drops in with the vinegar while it is soaking and it will colour the curds. Or make yours glow in the dark with our favourite trick!

Now squish it into your molds. We used silicone molds to make Lego minifigs and dinosaurs.

You can also shape it by hand. Roll it to create beads, then use a skewer to put a hole through it before setting it aside to dry. Or flatten it and use some cookie cutters.

The drying process takes time, approximately 2 days depending on your natural humidity levels and how much moisture you removed with the paper towels. But you can remove it from the silicone molds after 24 hours and this will help speed up the drying time.

Once dry, clean up the edges a bit if necessary, just like you would with any other casting. You can do this with just your fingers, a piece of sand paper or other tools. It will be hard plastic now, so it might take a little extra work!

You can paint the final products with either acrylic paints or markers. I used acrylic paints and a sharpie for the faces on mine. Spray them with a clear coat to give them a nice shine once you are finished.

VOILA! Who knew it was so easy, and so much fun, to make plastic from milk!

Our oldest Milk Plastic Toys are over 2 years old now and show no signs of degrading. We haven't done any experiments yet to see if they might break down with moisture, or heat, or sun, but that might go on the books for a future study. They are definitely highly durable!

This is a chemistry experiment working with polymers. Polymers are molecules that have formed a regular chain structure. Milk contains molecules of a protein called Casein. During this reaction between warm milk and acid the casein molecules unfold and form long chains called a polymer. The polymer can be molded and shaped which makes it a plastic. In this case it's called casein plastic or milk plastic because of the type of molecules that created the plastic.

More STEM activities

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Make Milk Plastic in the Kitchen Chemistry Project for Kids

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Make plastic from milk? It seems like some sort of lactose intolerant horror story, but it's actually a really cool science process. Create your own toys, beads, jewelry, and more, with ingredients you have right now in your kitchen. It's so easy and super cool! Disclaimer: This article may contain commission or affiliate links.

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I really liked this activity because one it is related back to Dr. Seuss and two it has to do with goo! I feel that students are always down for something that is kind of yucky.

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Have you ever read Dr. Seuss? I'm pretty sure everyone with kids has! Did you know that Dr. Seuss created the name of one of our favourite science experiments? Yup, Oobleck got it's name from Bartholomew and the Oobleck, a story about a bored king with a team of magicians at his disposal. You can imagine the chaos! So we created our own Bartholomew and the Oobleck inspired STEM activity to recreate the story. It was marvelously messy hands on STEM learning!

Bartholomew and the Oobleck - Dr. Seuss Inspired Learning
Disclaimer: This post contains affiliate links
Oobleck - non-Newtonian Fluid

We love a great science experiment, especially when it is a rule breaker like Oobleck. Known as a non-Newtonian fluid, oobleck breaks Newton's Laws of Fluid Dynamics. To understand this law think about how liquids normally behave. Water flows smoothly and freely, but mix in a bit of dirt to create mud and it slows down. This is because the dynamics (behaviours) of fluids are affected by their viscosity and density.

Want to learn more about the science of oobleck? Check out this article on our Colour Changing Oobleck or our Glow in the Dark Oobleck Activity for lots of great scientific details.

Dr. Seuss' Bartholomew and the Oobleck

As much as we love oobleck, we had never read the book that inspired the name. So I set out to get the book and add it to our collection. It turns out this was a little harder than I anticipated. See the book was published in 1949 (and won the Caldecott Honor-winning picture book 1950). Since this book is quite old, it wasn't available in any of my local bookstores. In the end I ordered it online. It was definitely worth it (even though I do prefer to visit bookstores in person!).

The book is about a bored king, King Derwin of Didd. Why is he so bored? He is bored by the weather. Sun, rain, fog and snow are just much too boring for him. So he tasks his team of royal magicians to create a new weather to make him happy.

The result is this sticky, gloppy creation that rains from the skies and creates complete havoc for the entire village.

In the end the king learns a valuable lesson about the power of words and we are introduced to the wonders of oobleck!

After reading the book we decided it would make amazing inspiration for a STEM activity.

Bartholomew and the Oobleck STEM Activity Supplies

To do this STEM activity you will need items you likely already have laying around the house.

Bartholomew and the Oobleck - it makes sense to have the book so you can do this as a full unit study!
Cornstarch
Water
Green food colouring
Bowl
Spoon
Lego - plates, blocks and minifigs
Some type of mesh (you could even build a grid from Lego pieces if you prefer)
Large, shallow edged dish
Easy to clean space

Bartholomew and the Oobleck Inspired STEM Project

After reading the book together, we were ready for our oobleck STEM activity.

First up we needed to build our "village". We built two walls with 2x bricks on a baseplate. Then we attached our mesh to the top. The weight of the oobleck did cause our walls to tip in. So we supported the walls with a few extra bricks at the bottom. Next time I would encourage the kids to come up with other ways to make the walls sturdier, such as adding beams or a grid to the top. This worked, but it wasn't the most stable construction with the weight of the oobleck added to the top.

Next we added our villagers! Don't they look like happy little villagers just going about their day? Except of course the oobleck raining down on their heads!

Once it was all built we carefully placed it all in a large shallow lipped tray to catch all the mess. Then we placed it on a table in an easy to clean up area. Oobleck is messy fun, so always plan ahead for easy clean up.

Now it was time to mix up our oobleck! Oobleck is soooo easy to make. Simply take 2 cups of cornstarch and 1 cup of water and add to a large bowl. Since the oobleck was green in Bartholomew and the Oobleck, we coloured our water green first before mixing it with the cornstarch.

Almost immediately you will start to see that non-Newtonian fluid dynamic as you try and mix it all together. The trick is to move slowly. The more pressure you place on the oobleck the harder it will get.

Once mixed it was time to reenact the book!

Oobleck, King Derwin and the Village of Didd

Before we started my son insisted on adding a minifig to represent King Derwin. He chose a knight and placed it at the very top, where he could see the chaos he unleashed on the people.

Now it was time for the magicians to unleash their magic goop - Oobleck!

We carefully scooped up the oobleck and added it to the top of our mesh. We watched as it would clump, then run, then clump and run. It was clump as it hit the mesh, then liquify and run through the mesh, but then it would clump again as it hit other bits of oobleck falling down. As it hit our village and our innocent villagers it would once again clump. It was fascinating to watch!

Now if your children have never used oobleck, you should spend some time letting them explore the properties of oobleck with their hands. It is such a cool substance that turns solid under pressure and liquefies when you remove the pressure. Having an understanding of those properties before starting this experiment will help them understand why it behaves in such a strange way as it rains down on their village.

The gloopy oobleck made for some really funny moments. Oobleck hat anyone?

CHECK OUT THE OOBLECK IN ACTION AS IT RAINS DOWN ON OUR VILLAGE!

MORE GREAT OOBLECK STUDIES

Oobleck is a fantastic science study. Check out some of our other oobleck projects.
Colour Changing Oobleck (acid-base study) Halloween Oobleck Game Glow in the Dark Oobleck Introduction to Oobleck
Have fun exploring this non-Newtonian fluid rule breaker in your science lessons!

MORE LEGO STEM ACTIVITIES

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Bartholomew and the Oobleck STEM Activity for elementary

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Have you ever read Dr. Seuss? I'm pretty sure everyone with kids has! Did you know that Dr. Seuss created the name of one of our favourite science experiments? Yup, Oobleck got it's name from Bartholomew and the Oobleck , a story about a bored king with a team of magicians at his disposal.

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I choose Ooblex because I made it before in elementary school! It is a fun experience for all ages. I also like how it incorporates language arts into a stem unit.  Kids get to create their Oobleck and then build on top of it. This lesson hits on many standards and lessons. The kids get to collaborate with one another and work on their critical thinking skills.
-Alexis Cancila

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Have you ever read Dr. Seuss? I'm pretty sure everyone with kids has! Did you know that Dr. Seuss created the name of one of our favourite science experiments? Yup, Oobleck got it's name from Bartholomew and the Oobleck, a story about a bored king with a team of magicians at his disposal. You can imagine the chaos! So we created our own Bartholomew and the Oobleck inspired STEM activity to recreate the story. It was marvelously messy hands on STEM learning!

Bartholomew and the Oobleck - Dr. Seuss Inspired Learning
Disclaimer: This post contains affiliate links
Oobleck - non-Newtonian Fluid

We love a great science experiment, especially when it is a rule breaker like Oobleck. Known as a non-Newtonian fluid, oobleck breaks Newton's Laws of Fluid Dynamics. To understand this law think about how liquids normally behave. Water flows smoothly and freely, but mix in a bit of dirt to create mud and it slows down. This is because the dynamics (behaviours) of fluids are affected by their viscosity and density.

Want to learn more about the science of oobleck? Check out this article on our Colour Changing Oobleck or our Glow in the Dark Oobleck Activity for lots of great scientific details.

Dr. Seuss' Bartholomew and the Oobleck

As much as we love oobleck, we had never read the book that inspired the name. So I set out to get the book and add it to our collection. It turns out this was a little harder than I anticipated. See the book was published in 1949 (and won the Caldecott Honor-winning picture book 1950). Since this book is quite old, it wasn't available in any of my local bookstores. In the end I ordered it online. It was definitely worth it (even though I do prefer to visit bookstores in person!).

The book is about a bored king, King Derwin of Didd. Why is he so bored? He is bored by the weather. Sun, rain, fog and snow are just much too boring for him. So he tasks his team of royal magicians to create a new weather to make him happy.

The result is this sticky, gloppy creation that rains from the skies and creates complete havoc for the entire village.

In the end the king learns a valuable lesson about the power of words and we are introduced to the wonders of oobleck!

After reading the book we decided it would make amazing inspiration for a STEM activity.

Bartholomew and the Oobleck STEM Activity Supplies

To do this STEM activity you will need items you likely already have laying around the house.

Bartholomew and the Oobleck - it makes sense to have the book so you can do this as a full unit study!
Cornstarch
Water
Green food colouring
Bowl
Spoon
Lego - plates, blocks and minifigs
Some type of mesh (you could even build a grid from Lego pieces if you prefer)
Large, shallow edged dish
Easy to clean space

Bartholomew and the Oobleck Inspired STEM Project

After reading the book together, we were ready for our oobleck STEM activity.

First up we needed to build our "village". We built two walls with 2x bricks on a baseplate. Then we attached our mesh to the top. The weight of the oobleck did cause our walls to tip in. So we supported the walls with a few extra bricks at the bottom. Next time I would encourage the kids to come up with other ways to make the walls sturdier, such as adding beams or a grid to the top. This worked, but it wasn't the most stable construction with the weight of the oobleck added to the top.

Next we added our villagers! Don't they look like happy little villagers just going about their day? Except of course the oobleck raining down on their heads!

Once it was all built we carefully placed it all in a large shallow lipped tray to catch all the mess. Then we placed it on a table in an easy to clean up area. Oobleck is messy fun, so always plan ahead for easy clean up.

Now it was time to mix up our oobleck! Oobleck is soooo easy to make. Simply take 2 cups of cornstarch and 1 cup of water and add to a large bowl. Since the oobleck was green in Bartholomew and the Oobleck, we coloured our water green first before mixing it with the cornstarch.

Almost immediately you will start to see that non-Newtonian fluid dynamic as you try and mix it all together. The trick is to move slowly. The more pressure you place on the oobleck the harder it will get.

Once mixed it was time to reenact the book!

Oobleck, King Derwin and the Village of Didd

Before we started my son insisted on adding a minifig to represent King Derwin. He chose a knight and placed it at the very top, where he could see the chaos he unleashed on the people.

Now it was time for the magicians to unleash their magic goop - Oobleck!

We carefully scooped up the oobleck and added it to the top of our mesh. We watched as it would clump, then run, then clump and run. It was clump as it hit the mesh, then liquify and run through the mesh, but then it would clump again as it hit other bits of oobleck falling down. As it hit our village and our innocent villagers it would once again clump. It was fascinating to watch!

Now if your children have never used oobleck, you should spend some time letting them explore the properties of oobleck with their hands. It is such a cool substance that turns solid under pressure and liquefies when you remove the pressure. Having an understanding of those properties before starting this experiment will help them understand why it behaves in such a strange way as it rains down on their village.

The gloopy oobleck made for some really funny moments. Oobleck hat anyone?

CHECK OUT THE OOBLECK IN ACTION AS IT RAINS DOWN ON OUR VILLAGE!

MORE GREAT OOBLECK STUDIES

Oobleck is a fantastic science study. Check out some of our other oobleck projects.
Colour Changing Oobleck (acid-base study) Halloween Oobleck Game Glow in the Dark Oobleck Introduction to Oobleck
Have fun exploring this non-Newtonian fluid rule breaker in your science lessons!

MORE LEGO STEM ACTIVITIES

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Bartholomew and the Oobleck STEM Activity for elementary

# data[].attributes.attachment_link.description
Have you ever read Dr. Seuss? I'm pretty sure everyone with kids has! Did you know that Dr. Seuss created the name of one of our favourite science experiments? Yup, Oobleck got it's name from Bartholomew and the Oobleck , a story about a bored king with a team of magicians at his disposal.

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I chose this lesson because this lesson is something you could also do at home not just in a classroom.
-Courtney Drennen

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Make plastic from milk? It seems like some sort of lactose intolerant horror story, but it's actually a really cool science process. Create your own toys, beads, jewelry, and more, with ingredients you have right now in your kitchen. It's so easy and super cool!

Turn Milk Into Plastic Toys!
Disclaimer: This article may contain commission or affiliate links. As an Amazon Associate I earn from qualifying purchases.
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Also known as casein plastic, this process has been used for over 100 years and is the way they used to make plastics before 1945 when synthetic plastics were introduced. Even royalty wore jewelry made from milk plastic many years ago. How cool is that?

With this simple process you can make toys, beads, jewelry, decorative pieces and more. This is a great, budget friendly experiment, with spectacular results that will have your students pumped with excitement for science!

A stove top or microwave to warm the milk
Milk (we used 2%, lower fat content is better)
White Vinegar or Lemon Juice
Bowl
Spoon
Strainer (or can create your own using cheese cloth or similar)
Paper towel
Molds (we loved using our Lego minifigures and Dinosaur molds) or other tools for shaping.

Time: 30 to 90 minutes for the experiment, then 2 days for drying. Add in a little extra time for painting once dry!

Measure out 1 cup of milk (you can also use chocolate milk and the end result smells amazing!), this makes about 4 minifigures or 4 dinosaurs. Heat on the stove top in a pot or in the microwave in a heat resistant bowl. You want it to just start steaming. Remove from the heat. Add 4 tsp of vinegar or lemon juice and stir gently.

The amount of vinegar is not exact. We used 4 tbsp by accident and it was fine, just made for a more intense vinegar smell!

You will notice that it immediately begins to curdle. You're making curds and whey!

Stir gently for approximately one minute for the full reaction to finish and all the curds to form. Don't stir aggressively. Be gentle.

Strain off the whey using a strainer or you can use cheese cloth (or similar). Let drip for a few minutes until most of the liquid has drained off. Gently smoosh the curds around in the strainer if needed.

Now remove the curds and place them on a few layers of paper towel. Carefully pat and squish to remove more liquid. You may need to replace the paper towel and repeat a few times. The goal is to remove as much liquid as possible.

You will notice it is kind of crumbly and squishy, but you can smoosh and shape it.

Now you can put it in your molds at this point but we discovered that if you put the curds in a jar or bowl, soaking in vinegar for an hour, you will get a much smoother final product. Plus they are more white if you do this extra step. If you do the extra vinegar soak, once the hour is up, repeat the straining, and paper towel drying process again. This time you will notice it is smoother in texture and no longer crumbly.

During the vinegar soak you can add some food colouring if you want. Just put a few drops in with the vinegar while it is soaking and it will colour the curds. Or make yours glow in the dark with our favourite trick!

Now squish it into your molds. We used silicone molds to make Lego minifigs and dinosaurs.

You can also shape it by hand. Roll it to create beads, then use a skewer to put a hole through it before setting it aside to dry. Or flatten it and use some cookie cutters.

The drying process takes time, approximately 2 days depending on your natural humidity levels and how much moisture you removed with the paper towels. But you can remove it from the silicone molds after 24 hours and this will help speed up the drying time.

Once dry, clean up the edges a bit if necessary, just like you would with any other casting. You can do this with just your fingers, a piece of sand paper or other tools. It will be hard plastic now, so it might take a little extra work!

You can paint the final products with either acrylic paints or markers. I used acrylic paints and a sharpie for the faces on mine. Spray them with a clear coat to give them a nice shine once you are finished.

VOILA! Who knew it was so easy, and so much fun, to make plastic from milk!

Our oldest Milk Plastic Toys are over 2 years old now and show no signs of degrading. We haven't done any experiments yet to see if they might break down with moisture, or heat, or sun, but that might go on the books for a future study. They are definitely highly durable!

This is a chemistry experiment working with polymers. Polymers are molecules that have formed a regular chain structure. Milk contains molecules of a protein called Casein. During this reaction between warm milk and acid the casein molecules unfold and form long chains called a polymer. The polymer can be molded and shaped which makes it a plastic. In this case it's called casein plastic or milk plastic because of the type of molecules that created the plastic.

More STEM activities

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Make Milk Plastic in the Kitchen Chemistry Project for Kids

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Make plastic from milk? It seems like some sort of lactose intolerant horror story, but it's actually a really cool science process. Create your own toys, beads, jewelry, and more, with ingredients you have right now in your kitchen. It's so easy and super cool! Disclaimer: This article may contain commission or affiliate links.

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I really liked both lessons, but I feel that the oobleck lesson would be more practical for a classroom. You can really bring in a stove or a microwave, which is a significant material needed. Oobleck would also be fun for the students. They would have to determine if it is a solid or a liquid, which would change if they are holding it or poking it. They will also be able to choose which color they want their oobleck to be!
~Sara Flood

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Have you ever read Dr. Seuss? I'm pretty sure everyone with kids has! Did you know that Dr. Seuss created the name of one of our favourite science experiments? Yup, Oobleck got it's name from Bartholomew and the Oobleck, a story about a bored king with a team of magicians at his disposal. You can imagine the chaos! So we created our own Bartholomew and the Oobleck inspired STEM activity to recreate the story. It was marvelously messy hands on STEM learning!

Bartholomew and the Oobleck - Dr. Seuss Inspired Learning
Disclaimer: This post contains affiliate links
Oobleck - non-Newtonian Fluid

We love a great science experiment, especially when it is a rule breaker like Oobleck. Known as a non-Newtonian fluid, oobleck breaks Newton's Laws of Fluid Dynamics. To understand this law think about how liquids normally behave. Water flows smoothly and freely, but mix in a bit of dirt to create mud and it slows down. This is because the dynamics (behaviours) of fluids are affected by their viscosity and density.

Want to learn more about the science of oobleck? Check out this article on our Colour Changing Oobleck or our Glow in the Dark Oobleck Activity for lots of great scientific details.

Dr. Seuss' Bartholomew and the Oobleck

As much as we love oobleck, we had never read the book that inspired the name. So I set out to get the book and add it to our collection. It turns out this was a little harder than I anticipated. See the book was published in 1949 (and won the Caldecott Honor-winning picture book 1950). Since this book is quite old, it wasn't available in any of my local bookstores. In the end I ordered it online. It was definitely worth it (even though I do prefer to visit bookstores in person!).

The book is about a bored king, King Derwin of Didd. Why is he so bored? He is bored by the weather. Sun, rain, fog and snow are just much too boring for him. So he tasks his team of royal magicians to create a new weather to make him happy.

The result is this sticky, gloppy creation that rains from the skies and creates complete havoc for the entire village.

In the end the king learns a valuable lesson about the power of words and we are introduced to the wonders of oobleck!

After reading the book we decided it would make amazing inspiration for a STEM activity.

Bartholomew and the Oobleck STEM Activity Supplies

To do this STEM activity you will need items you likely already have laying around the house.

Bartholomew and the Oobleck - it makes sense to have the book so you can do this as a full unit study!
Cornstarch
Water
Green food colouring
Bowl
Spoon
Lego - plates, blocks and minifigs
Some type of mesh (you could even build a grid from Lego pieces if you prefer)
Large, shallow edged dish
Easy to clean space

Bartholomew and the Oobleck Inspired STEM Project

After reading the book together, we were ready for our oobleck STEM activity.

First up we needed to build our "village". We built two walls with 2x bricks on a baseplate. Then we attached our mesh to the top. The weight of the oobleck did cause our walls to tip in. So we supported the walls with a few extra bricks at the bottom. Next time I would encourage the kids to come up with other ways to make the walls sturdier, such as adding beams or a grid to the top. This worked, but it wasn't the most stable construction with the weight of the oobleck added to the top.

Next we added our villagers! Don't they look like happy little villagers just going about their day? Except of course the oobleck raining down on their heads!

Once it was all built we carefully placed it all in a large shallow lipped tray to catch all the mess. Then we placed it on a table in an easy to clean up area. Oobleck is messy fun, so always plan ahead for easy clean up.

Now it was time to mix up our oobleck! Oobleck is soooo easy to make. Simply take 2 cups of cornstarch and 1 cup of water and add to a large bowl. Since the oobleck was green in Bartholomew and the Oobleck, we coloured our water green first before mixing it with the cornstarch.

Almost immediately you will start to see that non-Newtonian fluid dynamic as you try and mix it all together. The trick is to move slowly. The more pressure you place on the oobleck the harder it will get.

Once mixed it was time to reenact the book!

Oobleck, King Derwin and the Village of Didd

Before we started my son insisted on adding a minifig to represent King Derwin. He chose a knight and placed it at the very top, where he could see the chaos he unleashed on the people.

Now it was time for the magicians to unleash their magic goop - Oobleck!

We carefully scooped up the oobleck and added it to the top of our mesh. We watched as it would clump, then run, then clump and run. It was clump as it hit the mesh, then liquify and run through the mesh, but then it would clump again as it hit other bits of oobleck falling down. As it hit our village and our innocent villagers it would once again clump. It was fascinating to watch!

Now if your children have never used oobleck, you should spend some time letting them explore the properties of oobleck with their hands. It is such a cool substance that turns solid under pressure and liquefies when you remove the pressure. Having an understanding of those properties before starting this experiment will help them understand why it behaves in such a strange way as it rains down on their village.

The gloopy oobleck made for some really funny moments. Oobleck hat anyone?

CHECK OUT THE OOBLECK IN ACTION AS IT RAINS DOWN ON OUR VILLAGE!

MORE GREAT OOBLECK STUDIES

Oobleck is a fantastic science study. Check out some of our other oobleck projects.
Colour Changing Oobleck (acid-base study) Halloween Oobleck Game Glow in the Dark Oobleck Introduction to Oobleck
Have fun exploring this non-Newtonian fluid rule breaker in your science lessons!

MORE LEGO STEM ACTIVITIES

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Bartholomew and the Oobleck STEM Activity for elementary

# data[].attributes.attachment_link.description
Have you ever read Dr. Seuss? I'm pretty sure everyone with kids has! Did you know that Dr. Seuss created the name of one of our favourite science experiments? Yup, Oobleck got it's name from Bartholomew and the Oobleck , a story about a bored king with a team of magicians at his disposal.

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I really like how this lesson plan integrates technology with learning facts about animals and new vocabulary. I could definately use this lesson to teach one concept, and the kids would end up learning more then one.
-Ally Green

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Creature Powers: Lesson Plan | PBS KIDS ScratchJr | PBS LearningMedia

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Animate animal traits with the WILD KRATTS!

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Tiffany Blose
I really like this lesson because it is really easy to do and set up. It is a great way to show students how energy and heat works. It is a very hands on and engaging lesson.

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I love my girls' natural curiosity when it comes to science. So, when my daughter asked me "Can we do a hot chocolate science experiment?" I knew it was time to get creative.

Working together, we came up with an amazing STEM activity.

When we make instant hot chocolate, we dissolve the contents of the packet into hot water. We decided to find out if temperature affected the speed that it dissolves.

Let's get started!

Disclosure: There are Amazon Affiliate and other affiliate links in this article which means, at no additional cost to you, we could receive compensation for our recommendations. You can read our full disclosure policy on our Disclosure Page for more details.

Supplies Needed for Your Hot Chocolate Science Project

First we needed to gather our supplies. Luckily most of the items were already in our kitchen.

Here's what you'll need:

Three heat-proof mugs
Three packets of instant hot chocolate
Measuring cup
Water
Spoons
Stopwatch or timer
Notebook for recording your results.

How to Do Your Hot Chocolate Science Experiment

We started our experiment by making a prediction. Which temperature of water would dissolve the hot chocolate the quickest?

The girls made their prediction (they chose hot) and then it was time to experiment.

We started by emptying our hot chocolate packets into our mugs, one packet per mug. Then we moved on to testing the different temperatures of water.

We tested each temperature, one at a time. We were very vague with our temperatures, using ice cold water, room temperature water, and hot water. You can always add a kitchen thermometer to measure the temperature of the water to add an extra measurement element to your experiment.

My girls took turns measuring the water, stirring, and operating the stopwatch. We used the digital stopwatch on my phone to time how long the hot chocolate took to dissolve.

For each cup, we measured 6 oz. of water. We used cold water from our refrigerator over ice, lukewarm water from the tap, and I did my grown-up duty and heated water in the microwave for the last mug.

Once the water was added to a mug, one girl started the stopwatch and the other started stirring. We stopped the stopwatch as soon as we saw the hot chocolate had dissolved.

Does Hot Chocolate Dissolve Faster in Hot Water or Cold Water?

We started with the ice cold water. My oldest daughter was in charge of the stirring. She stirred and stirred and stirred some more. It wouldn't dissolve. Eventually, we made the decision to stop after three minutes. You can see the results above. Disgusting!

We moved on to the room temperature water, which clocked in at 1 minute 38 seconds. And, then the hot water, which only took 28 seconds.

The results: hot water takes the least amount of time. We predicted that because the instructions said to use hot water when we made hot chocolate. (And, it's called hot chocolate after all...) But, now we know why we need to use hot water.

Why Does Hot Chocolate Powder Dissolve Faster in Hot Water?

Hot water has more energy than cold water. With more energy, the molecules in the water move faster breaking down the hot chocolate mix quicker.

Once we finished writing our results, we unceremoniously dumped the cold water hot chocolate sludge down the kitchen sink. Ick.

What happened to the other two mugs? They were topped with a dollop of whipped cream and enjoyed!

Our hot chocolate science experiment and turned out great!

More STEAM Activities to Try
Hockey Science Christmas Science: Grow the Grinch's Heart Edible STEM Projects for Kids Marshmallow Engineering STEAM Building Challenge 28 Awesome STEM Challenges for the Elementary Classroom at Teach Junkie
STEM Activities for Kids in the Kitchen at iGame Mom

Do more science at home:

We love Green Kid Crafts boxes because they provide easy, ready-to-do STEM activities we can try at home. You'll receive easy-to-follow instructions plus the supplies that you need for up to 6 activities. You can get a monthly subscription or buy a single themed box. If you enjoyed our hot chocolate science experiment, you may enjoy the Kitchen Science or the monthly Discovery Box subscription.

Click here for the Kitchen Science box.

Click here for the monthly Discovery Box subscription.

Are you looking for more activities?

Join our fun Facebook community, Creative Family Fun for Busy Families, for daily activities that are great for kids and families. We'll chat, share, and have fun. It's a safe and private place to share idea for family and kids activities. I'd love for you to join me! Just click the link below, request to join, and answer the questions (they're easy, I promise). Come join the fun! Join the Creative Family Fun for Busy Families community here.

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This hot chocolate science experiment is a fun way to learn about how temperature affects the rate at which hot chocolate dissolves.

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I like this lesson the best because it can be done anytime of the year. I feel as though hot chocolate will not be interesting in the hotter days of school rather than kids are always in the mood for candy! It includes different ways to use jelly beans in science such as shape, structure, and physical properties.

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What's cheaper than a Peep? Jelly beans! They're everywhere and after Easter, stores mark them half off. I have 3 Easter science activities to share with you today that are awesome for your elementary students. Keep it simple or take them to the next level!

Solubility

The first activity addresses solutions, solutes, solvents, and concentration. There are several ways you can do this, but here is one of them.
Use different amounts of warm water (100ml and 25ml) to dissolve 2 jelly bean candy shells. (A little white part will remain that you can toss.) You can use *strong* baggies or cups for the water. Identify how the transparency of the color depends on the concentration.

Physical Properties

Identify the physical properties of a jelly bean. Mix them together in a group. Do the physical properties of the jelly bean change? Place the jelly bean in water. How do the physical properties of the jelly bean change?

Jelly Bean Towers

Provide each student with 10 toothpicks and 10 jelly beans. The challenge to create the tallest stable tower possible. There must be a jelly bean at the top of the tower. Identify weak levels and strong levels. Provide students an opportunity to draw their designs and refine them.

Happy Easter!

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Easter Science Activities with Jelly Beans

# data[].attributes.attachment_link.description
What's cheaper than a Peep? Jelly beans! They're everywhere and after Easter, stores mark them half off. I have 3 Easter science activities to share with you today that are awesome for your elementary students. Keep it simple or take them to the next level! The first activity addresses solutions, solutes, solvents, and concentration.

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I really like the jelly bean lesson plan because it involves solubility, however I feel as if hot chocolate will bring more attention to the students. Students get to observe solubility and how it works with temperature.

# data[].attributes.attachment_link.readable_text
I love my girls' natural curiosity when it comes to science. So, when my daughter asked me "Can we do a hot chocolate science experiment?" I knew it was time to get creative.

Working together, we came up with an amazing STEM activity.

When we make instant hot chocolate, we dissolve the contents of the packet into hot water. We decided to find out if temperature affected the speed that it dissolves.

Let's get started!

Disclosure: There are Amazon Affiliate and other affiliate links in this article which means, at no additional cost to you, we could receive compensation for our recommendations. You can read our full disclosure policy on our Disclosure Page for more details.

Supplies Needed for Your Hot Chocolate Science Project

First we needed to gather our supplies. Luckily most of the items were already in our kitchen.

Here's what you'll need:

Three heat-proof mugs
Three packets of instant hot chocolate
Measuring cup
Water
Spoons
Stopwatch or timer
Notebook for recording your results.

How to Do Your Hot Chocolate Science Experiment

We started our experiment by making a prediction. Which temperature of water would dissolve the hot chocolate the quickest?

The girls made their prediction (they chose hot) and then it was time to experiment.

We started by emptying our hot chocolate packets into our mugs, one packet per mug. Then we moved on to testing the different temperatures of water.

We tested each temperature, one at a time. We were very vague with our temperatures, using ice cold water, room temperature water, and hot water. You can always add a kitchen thermometer to measure the temperature of the water to add an extra measurement element to your experiment.

My girls took turns measuring the water, stirring, and operating the stopwatch. We used the digital stopwatch on my phone to time how long the hot chocolate took to dissolve.

For each cup, we measured 6 oz. of water. We used cold water from our refrigerator over ice, lukewarm water from the tap, and I did my grown-up duty and heated water in the microwave for the last mug.

Once the water was added to a mug, one girl started the stopwatch and the other started stirring. We stopped the stopwatch as soon as we saw the hot chocolate had dissolved.

Does Hot Chocolate Dissolve Faster in Hot Water or Cold Water?

We started with the ice cold water. My oldest daughter was in charge of the stirring. She stirred and stirred and stirred some more. It wouldn't dissolve. Eventually, we made the decision to stop after three minutes. You can see the results above. Disgusting!

We moved on to the room temperature water, which clocked in at 1 minute 38 seconds. And, then the hot water, which only took 28 seconds.

The results: hot water takes the least amount of time. We predicted that because the instructions said to use hot water when we made hot chocolate. (And, it's called hot chocolate after all...) But, now we know why we need to use hot water.

Why Does Hot Chocolate Powder Dissolve Faster in Hot Water?

Hot water has more energy than cold water. With more energy, the molecules in the water move faster breaking down the hot chocolate mix quicker.

Once we finished writing our results, we unceremoniously dumped the cold water hot chocolate sludge down the kitchen sink. Ick.

What happened to the other two mugs? They were topped with a dollop of whipped cream and enjoyed!

Our hot chocolate science experiment and turned out great!

More STEAM Activities to Try
Hockey Science Christmas Science: Grow the Grinch's Heart Edible STEM Projects for Kids Marshmallow Engineering STEAM Building Challenge 28 Awesome STEM Challenges for the Elementary Classroom at Teach Junkie
STEM Activities for Kids in the Kitchen at iGame Mom

Do more science at home:

We love Green Kid Crafts boxes because they provide easy, ready-to-do STEM activities we can try at home. You'll receive easy-to-follow instructions plus the supplies that you need for up to 6 activities. You can get a monthly subscription or buy a single themed box. If you enjoyed our hot chocolate science experiment, you may enjoy the Kitchen Science or the monthly Discovery Box subscription.

Click here for the Kitchen Science box.

Click here for the monthly Discovery Box subscription.

Are you looking for more activities?

Join our fun Facebook community, Creative Family Fun for Busy Families, for daily activities that are great for kids and families. We'll chat, share, and have fun. It's a safe and private place to share idea for family and kids activities. I'd love for you to join me! Just click the link below, request to join, and answer the questions (they're easy, I promise). Come join the fun! Join the Creative Family Fun for Busy Families community here.

The following two tabs change content below.

# data[].attributes.attachment_link.description
This hot chocolate science experiment is a fun way to learn about how temperature affects the rate at which hot chocolate dissolves.

# data[].attributes.body
I really like how this can incorporate the different parts of experiments in the science lab. This incorporates prediction along with the movement of molecules. I feel like this would be better for the third grade range rather than first grade.
Kenzie Bullock

# data[].attributes.attachment_link.readable_text
I love my girls' natural curiosity when it comes to science. So, when my daughter asked me "Can we do a hot chocolate science experiment?" I knew it was time to get creative.

Working together, we came up with an amazing STEM activity.

When we make instant hot chocolate, we dissolve the contents of the packet into hot water. We decided to find out if temperature affected the speed that it dissolves.

Let's get started!

Disclosure: There are Amazon Affiliate and other affiliate links in this article which means, at no additional cost to you, we could receive compensation for our recommendations. You can read our full disclosure policy on our Disclosure Page for more details.

Supplies Needed for Your Hot Chocolate Science Project

First we needed to gather our supplies. Luckily most of the items were already in our kitchen.

Here's what you'll need:

Three heat-proof mugs
Three packets of instant hot chocolate
Measuring cup
Water
Spoons
Stopwatch or timer
Notebook for recording your results.

How to Do Your Hot Chocolate Science Experiment

We started our experiment by making a prediction. Which temperature of water would dissolve the hot chocolate the quickest?

The girls made their prediction (they chose hot) and then it was time to experiment.

We started by emptying our hot chocolate packets into our mugs, one packet per mug. Then we moved on to testing the different temperatures of water.

We tested each temperature, one at a time. We were very vague with our temperatures, using ice cold water, room temperature water, and hot water. You can always add a kitchen thermometer to measure the temperature of the water to add an extra measurement element to your experiment.

My girls took turns measuring the water, stirring, and operating the stopwatch. We used the digital stopwatch on my phone to time how long the hot chocolate took to dissolve.

For each cup, we measured 6 oz. of water. We used cold water from our refrigerator over ice, lukewarm water from the tap, and I did my grown-up duty and heated water in the microwave for the last mug.

Once the water was added to a mug, one girl started the stopwatch and the other started stirring. We stopped the stopwatch as soon as we saw the hot chocolate had dissolved.

Does Hot Chocolate Dissolve Faster in Hot Water or Cold Water?

We started with the ice cold water. My oldest daughter was in charge of the stirring. She stirred and stirred and stirred some more. It wouldn't dissolve. Eventually, we made the decision to stop after three minutes. You can see the results above. Disgusting!

We moved on to the room temperature water, which clocked in at 1 minute 38 seconds. And, then the hot water, which only took 28 seconds.

The results: hot water takes the least amount of time. We predicted that because the instructions said to use hot water when we made hot chocolate. (And, it's called hot chocolate after all...) But, now we know why we need to use hot water.

Why Does Hot Chocolate Powder Dissolve Faster in Hot Water?

Hot water has more energy than cold water. With more energy, the molecules in the water move faster breaking down the hot chocolate mix quicker.

Once we finished writing our results, we unceremoniously dumped the cold water hot chocolate sludge down the kitchen sink. Ick.

What happened to the other two mugs? They were topped with a dollop of whipped cream and enjoyed!

Our hot chocolate science experiment and turned out great!

More STEAM Activities to Try
Hockey Science Christmas Science: Grow the Grinch's Heart Edible STEM Projects for Kids Marshmallow Engineering STEAM Building Challenge 28 Awesome STEM Challenges for the Elementary Classroom at Teach Junkie
STEM Activities for Kids in the Kitchen at iGame Mom

Do more science at home:

We love Green Kid Crafts boxes because they provide easy, ready-to-do STEM activities we can try at home. You'll receive easy-to-follow instructions plus the supplies that you need for up to 6 activities. You can get a monthly subscription or buy a single themed box. If you enjoyed our hot chocolate science experiment, you may enjoy the Kitchen Science or the monthly Discovery Box subscription.

Click here for the Kitchen Science box.

Click here for the monthly Discovery Box subscription.

Are you looking for more activities?

Join our fun Facebook community, Creative Family Fun for Busy Families, for daily activities that are great for kids and families. We'll chat, share, and have fun. It's a safe and private place to share idea for family and kids activities. I'd love for you to join me! Just click the link below, request to join, and answer the questions (they're easy, I promise). Come join the fun! Join the Creative Family Fun for Busy Families community here.

The following two tabs change content below.

# data[].attributes.attachment_link.description
This hot chocolate science experiment is a fun way to learn about how temperature affects the rate at which hot chocolate dissolves.

# data[].attributes.body
I chose this lesson for its simplicity, but also the information that it teaches. It implicated making predictions, which I think is important for students to do.
- Rachel Achey

# data[].attributes.attachment_link.readable_text
I love my girls' natural curiosity when it comes to science. So, when my daughter asked me "Can we do a hot chocolate science experiment?" I knew it was time to get creative.

Working together, we came up with an amazing STEM activity.

When we make instant hot chocolate, we dissolve the contents of the packet into hot water. We decided to find out if temperature affected the speed that it dissolves.

Let's get started!

Disclosure: There are Amazon Affiliate and other affiliate links in this article which means, at no additional cost to you, we could receive compensation for our recommendations. You can read our full disclosure policy on our Disclosure Page for more details.

Supplies Needed for Your Hot Chocolate Science Project

First we needed to gather our supplies. Luckily most of the items were already in our kitchen.

Here's what you'll need:

Three heat-proof mugs
Three packets of instant hot chocolate
Measuring cup
Water
Spoons
Stopwatch or timer
Notebook for recording your results.

How to Do Your Hot Chocolate Science Experiment

We started our experiment by making a prediction. Which temperature of water would dissolve the hot chocolate the quickest?

The girls made their prediction (they chose hot) and then it was time to experiment.

We started by emptying our hot chocolate packets into our mugs, one packet per mug. Then we moved on to testing the different temperatures of water.

We tested each temperature, one at a time. We were very vague with our temperatures, using ice cold water, room temperature water, and hot water. You can always add a kitchen thermometer to measure the temperature of the water to add an extra measurement element to your experiment.

My girls took turns measuring the water, stirring, and operating the stopwatch. We used the digital stopwatch on my phone to time how long the hot chocolate took to dissolve.

For each cup, we measured 6 oz. of water. We used cold water from our refrigerator over ice, lukewarm water from the tap, and I did my grown-up duty and heated water in the microwave for the last mug.

Once the water was added to a mug, one girl started the stopwatch and the other started stirring. We stopped the stopwatch as soon as we saw the hot chocolate had dissolved.

Does Hot Chocolate Dissolve Faster in Hot Water or Cold Water?

We started with the ice cold water. My oldest daughter was in charge of the stirring. She stirred and stirred and stirred some more. It wouldn't dissolve. Eventually, we made the decision to stop after three minutes. You can see the results above. Disgusting!

We moved on to the room temperature water, which clocked in at 1 minute 38 seconds. And, then the hot water, which only took 28 seconds.

The results: hot water takes the least amount of time. We predicted that because the instructions said to use hot water when we made hot chocolate. (And, it's called hot chocolate after all...) But, now we know why we need to use hot water.

Why Does Hot Chocolate Powder Dissolve Faster in Hot Water?

Hot water has more energy than cold water. With more energy, the molecules in the water move faster breaking down the hot chocolate mix quicker.

Once we finished writing our results, we unceremoniously dumped the cold water hot chocolate sludge down the kitchen sink. Ick.

What happened to the other two mugs? They were topped with a dollop of whipped cream and enjoyed!

Our hot chocolate science experiment and turned out great!

More STEAM Activities to Try
Hockey Science Christmas Science: Grow the Grinch's Heart Edible STEM Projects for Kids Marshmallow Engineering STEAM Building Challenge 28 Awesome STEM Challenges for the Elementary Classroom at Teach Junkie
STEM Activities for Kids in the Kitchen at iGame Mom

Do more science at home:

We love Green Kid Crafts boxes because they provide easy, ready-to-do STEM activities we can try at home. You'll receive easy-to-follow instructions plus the supplies that you need for up to 6 activities. You can get a monthly subscription or buy a single themed box. If you enjoyed our hot chocolate science experiment, you may enjoy the Kitchen Science or the monthly Discovery Box subscription.

Click here for the Kitchen Science box.

Click here for the monthly Discovery Box subscription.

Are you looking for more activities?

Join our fun Facebook community, Creative Family Fun for Busy Families, for daily activities that are great for kids and families. We'll chat, share, and have fun. It's a safe and private place to share idea for family and kids activities. I'd love for you to join me! Just click the link below, request to join, and answer the questions (they're easy, I promise). Come join the fun! Join the Creative Family Fun for Busy Families community here.

The following two tabs change content below.

# data[].attributes.attachment_link.description
This hot chocolate science experiment is a fun way to learn about how temperature affects the rate at which hot chocolate dissolves.

# data[].attributes.headline
I liked the Jelly Bean Science experiment because I think it would be cool to do across a period of time in the classroom. Like maybe I could have all of us put them in water before lunch then come back and see what has happened and record it in a science journal. I also think this might be considered STEAM just because it involves color that maybe they could paint or something with the jelly bean water. 

# data[].attributes.subject
I liked the Jelly Bean Science experiment because I think it would be cool to do across a period of time in the classroom. Like maybe I could have all of us put them in water before lunch then come back and see what has happened and record it in a science journal. I also think this might be considered STEAM just because it involves color that maybe they could paint or something with the jelly bean water. 

# data[].attributes.body
- Emily Doerschuk

# data[].attributes.attachment_link.readable_text
What's cheaper than a Peep? Jelly beans! They're everywhere and after Easter, stores mark them half off. I have 3 Easter science activities to share with you today that are awesome for your elementary students. Keep it simple or take them to the next level!

Solubility

The first activity addresses solutions, solutes, solvents, and concentration. There are several ways you can do this, but here is one of them.
Use different amounts of warm water (100ml and 25ml) to dissolve 2 jelly bean candy shells. (A little white part will remain that you can toss.) You can use *strong* baggies or cups for the water. Identify how the transparency of the color depends on the concentration.

Physical Properties

Identify the physical properties of a jelly bean. Mix them together in a group. Do the physical properties of the jelly bean change? Place the jelly bean in water. How do the physical properties of the jelly bean change?

Jelly Bean Towers

Provide each student with 10 toothpicks and 10 jelly beans. The challenge to create the tallest stable tower possible. There must be a jelly bean at the top of the tower. Identify weak levels and strong levels. Provide students an opportunity to draw their designs and refine them.

Happy Easter!

# data[].attributes.attachment_link.title
Easter Science Activities with Jelly Beans

# data[].attributes.attachment_link.description
What's cheaper than a Peep? Jelly beans! They're everywhere and after Easter, stores mark them half off. I have 3 Easter science activities to share with you today that are awesome for your elementary students. Keep it simple or take them to the next level! The first activity addresses solutions, solutes, solvents, and concentration.

# data[].attributes.body
I really liked the jelly bean lesson because it teaches about solubility in a fun and understandable way. It does not require many materials, and could even be adapted to use different types of candy. -Grace Rhine

# data[].attributes.body
I liked the jelly bean lesson, specifically the structure one where you build something using toothpicks and jelly beans. I think it is fun and it allows children to use their creativity to create something out of little materials. It is also cheap and safe which is always a plus. It includes many 21st century skills as well!

# data[].attributes.attachment_link.readable_text
What's cheaper than a Peep? Jelly beans! They're everywhere and after Easter, stores mark them half off. I have 3 Easter science activities to share with you today that are awesome for your elementary students. Keep it simple or take them to the next level!

Solubility

The first activity addresses solutions, solutes, solvents, and concentration. There are several ways you can do this, but here is one of them.
Use different amounts of warm water (100ml and 25ml) to dissolve 2 jelly bean candy shells. (A little white part will remain that you can toss.) You can use *strong* baggies or cups for the water. Identify how the transparency of the color depends on the concentration.

Physical Properties

Identify the physical properties of a jelly bean. Mix them together in a group. Do the physical properties of the jelly bean change? Place the jelly bean in water. How do the physical properties of the jelly bean change?

Jelly Bean Towers

Provide each student with 10 toothpicks and 10 jelly beans. The challenge to create the tallest stable tower possible. There must be a jelly bean at the top of the tower. Identify weak levels and strong levels. Provide students an opportunity to draw their designs and refine them.

Happy Easter!

# data[].attributes.attachment_link.title
Easter Science Activities with Jelly Beans

# data[].attributes.attachment_link.description
What's cheaper than a Peep? Jelly beans! They're everywhere and after Easter, stores mark them half off. I have 3 Easter science activities to share with you today that are awesome for your elementary students. Keep it simple or take them to the next level! The first activity addresses solutions, solutes, solvents, and concentration.

# data[].attributes.body
I think that the picture hunt is the best lesson. It is different and it allows students to see that science exists all around you. It can make students see that things may be more than just they seem and that they can be more than one thing. It is great for use of technology too because the students are finding the object/shape and taking a photograph of it as well.

# data[].attributes.attachment_link.readable_text
I've wanted to do a photo scavenger hunt with the kids for a long, long time. I always love any kind of scavenger hunt. And the boys love taking photos.

But the boys don't have their own camera, and all I have is my DSLR that I use (affiliate link) and I don't want to hand that over to the boys (I'm nervous of it breaking... and I couldn't go without it until I got it replaced).

I finally realized that the iPad mini (affiliate link) that we have can be used! Duh! It took me forever to come up with this solution.

Even better, it let me put the photo scavenger hunt right on the iPad for the kids to search for and then have George take photos of what he found.

I decided to hunt around the yard to find different shapes of objects. A square, circle, triangle and rectangle.

Triangles were the hardest to find, but found them in spokes of the cars and bikes.

Squares I found in our porch railing and skirting.

Circles were everywhere! I found a bell on their bikes, the ends of hoses, wheels of the million toys we have.

I took about a dozen photos of shapes I found around the yard and stored them in an album on the iPad for George.

George then took the iPad around the yard to find those shapes.

Once he found it, he switched over to the camera app to snap a photo of it too.

I have a collection of both my photos and his photos and its fun to compare the two!

Below is my photo for the triangle (I didn't have the red triangle and text in the photos, I just added that for this post to be clear).

And below is the photo that George took of the triangles he found.

He got the shape and object in every photo. But definitely not the same photo!

Below is my rectangle photo of a brick on the side of our house.

And below is George's version of the rectangle.

He didn't crop up nearly as close (maybe because I've told him time and time again to stay out of my plant beds and he's finally learning to listen).

This is the photo I took of the circle, a bell on his bike.

George tried to get it just the same! He did awesome hunting for them and finding the shapes!

This is his photo of the circle bell.

This photo scavenger hunt for the kids wasn't nearly as daunting as I thought it would be to put together. It took all of five minutes for me to walk around and find the shapes and snap the photos.

George loves anything to do with technology, so using the iPad to go on the scavenger hunt was a winner. Plus he got to take photos which he loves to do with it.

Got a hunter? The kids will love to go on any of these 32 ideas for scavenger hunts!

And in the meantime, he practiced his shapes. Triangles are still tough for him, but he's got squares and rectangles down now!

More move and learn ideas:

# data[].attributes.attachment_link.title
Photo Scavenger Hunt for Kids to Find Shapes

# data[].attributes.attachment_link.description
I've wanted to do a photo scavenger hunt with the kids for a long, long time. I always love any kind of scavenger hunt. And the boys love taking photos. But the boys don't have their own camera, and all I have is my DSLR that I use (affiliate link) and I don't want to hand that over to the boys (I'm nervous of it breaking...

# data[].attributes.body
Tiffany Blose
This activity is really easy to do and super engaging. It allows students to see things that they are learning about in real life. This lesson can be used in almost an grade.

# data[].attributes.attachment_link.readable_text
I've wanted to do a photo scavenger hunt with the kids for a long, long time. I always love any kind of scavenger hunt. And the boys love taking photos.

But the boys don't have their own camera, and all I have is my DSLR that I use (affiliate link) and I don't want to hand that over to the boys (I'm nervous of it breaking... and I couldn't go without it until I got it replaced).

I finally realized that the iPad mini (affiliate link) that we have can be used! Duh! It took me forever to come up with this solution.

Even better, it let me put the photo scavenger hunt right on the iPad for the kids to search for and then have George take photos of what he found.

I decided to hunt around the yard to find different shapes of objects. A square, circle, triangle and rectangle.

Triangles were the hardest to find, but found them in spokes of the cars and bikes.

Squares I found in our porch railing and skirting.

Circles were everywhere! I found a bell on their bikes, the ends of hoses, wheels of the million toys we have.

I took about a dozen photos of shapes I found around the yard and stored them in an album on the iPad for George.

George then took the iPad around the yard to find those shapes.

Once he found it, he switched over to the camera app to snap a photo of it too.

I have a collection of both my photos and his photos and its fun to compare the two!

Below is my photo for the triangle (I didn't have the red triangle and text in the photos, I just added that for this post to be clear).

And below is the photo that George took of the triangles he found.

He got the shape and object in every photo. But definitely not the same photo!

Below is my rectangle photo of a brick on the side of our house.

And below is George's version of the rectangle.

He didn't crop up nearly as close (maybe because I've told him time and time again to stay out of my plant beds and he's finally learning to listen).

This is the photo I took of the circle, a bell on his bike.

George tried to get it just the same! He did awesome hunting for them and finding the shapes!

This is his photo of the circle bell.

This photo scavenger hunt for the kids wasn't nearly as daunting as I thought it would be to put together. It took all of five minutes for me to walk around and find the shapes and snap the photos.

George loves anything to do with technology, so using the iPad to go on the scavenger hunt was a winner. Plus he got to take photos which he loves to do with it.

Got a hunter? The kids will love to go on any of these 32 ideas for scavenger hunts!

And in the meantime, he practiced his shapes. Triangles are still tough for him, but he's got squares and rectangles down now!

More move and learn ideas:

# data[].attributes.attachment_link.title
Photo Scavenger Hunt for Kids to Find Shapes

# data[].attributes.attachment_link.description
I've wanted to do a photo scavenger hunt with the kids for a long, long time. I always love any kind of scavenger hunt. And the boys love taking photos. But the boys don't have their own camera, and all I have is my DSLR that I use (affiliate link) and I don't want to hand that over to the boys (I'm nervous of it breaking...

# data[].attributes.body
I chose this lesson because I love the fact that it has students getting up and moving. This is super important for kids! It also included math through the lesson which I also thought was interesting.
- Rachel Achey

# data[].attributes.attachment_link.readable_text
I've wanted to do a photo scavenger hunt with the kids for a long, long time. I always love any kind of scavenger hunt. And the boys love taking photos.

But the boys don't have their own camera, and all I have is my DSLR that I use (affiliate link) and I don't want to hand that over to the boys (I'm nervous of it breaking... and I couldn't go without it until I got it replaced).

I finally realized that the iPad mini (affiliate link) that we have can be used! Duh! It took me forever to come up with this solution.

Even better, it let me put the photo scavenger hunt right on the iPad for the kids to search for and then have George take photos of what he found.

I decided to hunt around the yard to find different shapes of objects. A square, circle, triangle and rectangle.

Triangles were the hardest to find, but found them in spokes of the cars and bikes.

Squares I found in our porch railing and skirting.

Circles were everywhere! I found a bell on their bikes, the ends of hoses, wheels of the million toys we have.

I took about a dozen photos of shapes I found around the yard and stored them in an album on the iPad for George.

George then took the iPad around the yard to find those shapes.

Once he found it, he switched over to the camera app to snap a photo of it too.

I have a collection of both my photos and his photos and its fun to compare the two!

Below is my photo for the triangle (I didn't have the red triangle and text in the photos, I just added that for this post to be clear).

And below is the photo that George took of the triangles he found.

He got the shape and object in every photo. But definitely not the same photo!

Below is my rectangle photo of a brick on the side of our house.

And below is George's version of the rectangle.

He didn't crop up nearly as close (maybe because I've told him time and time again to stay out of my plant beds and he's finally learning to listen).

This is the photo I took of the circle, a bell on his bike.

George tried to get it just the same! He did awesome hunting for them and finding the shapes!

This is his photo of the circle bell.

This photo scavenger hunt for the kids wasn't nearly as daunting as I thought it would be to put together. It took all of five minutes for me to walk around and find the shapes and snap the photos.

George loves anything to do with technology, so using the iPad to go on the scavenger hunt was a winner. Plus he got to take photos which he loves to do with it.

Got a hunter? The kids will love to go on any of these 32 ideas for scavenger hunts!

And in the meantime, he practiced his shapes. Triangles are still tough for him, but he's got squares and rectangles down now!

More move and learn ideas:

# data[].attributes.attachment_link.title
Photo Scavenger Hunt for Kids to Find Shapes

# data[].attributes.attachment_link.description
I've wanted to do a photo scavenger hunt with the kids for a long, long time. I always love any kind of scavenger hunt. And the boys love taking photos. But the boys don't have their own camera, and all I have is my DSLR that I use (affiliate link) and I don't want to hand that over to the boys (I'm nervous of it breaking...

# data[].attributes.body
I liked the photo scavenger hunt because it is simple to understand and involves a fun way to practice shapes for the students. It allows the students to move around rather than sit at a desk all day, and can also let them use their creativity to complete the assignment by finding shapes in everyday objects. -Grace Rhine
https://handsonaswegrow.com/photo-scavenger-hunt-kids-shapes/

# data[].attributes.body
Tiffany Blose
This lesson is really fun and interesting. This is because if a student can make power from a potato that will blow their minds, it would even blow my mind.

# data[].attributes.attachment_link.readable_text
Quick Look

Grade Level: 4 (3-5)

Time Required: 45 minutes

Expendable Cost/Group: US $2.00

Group Size: 3

Activity Dependency: None

Subject Areas: Physical Science, Science and Technology

NGSS Performance Expectations:

Summary Students use potatoes to light an LED clock (or light bulb) as they learn how a battery works in a simple circuit and how chemical energy changes to electrical energy. As they learn more about electrical energy, they better understand the concepts of voltage, current and resistance.
This engineering curriculum aligns to Next Generation Science Standards (NGSS).

Engineering Connection

Engineers use batteries to store energy in a wide range of situations. A solid electrolyte battery is most suitable in very extreme weather conditions, while nickel-zinc batteries work best in electric vehicles. Energy engineers continually evolve technology to improve the performance and life-cycle costs of batteries that store solar and wind energy. When designing a battery, engineers keep in mind the needs of the application, and use different substances to create current flow. They consider characteristics such as power output, ability to recharge, reliability, size, safety, heat generation, length of life cycle, abuse tolerance, cost and ability to be recycled. Isn't the power of engineering creativity amazing?

Learning Objectives

After this activity, students should be able to:

Describe the flow of electrical energy through a simple circuit.

Explain why a light bulb may take more than one battery to light up.

Explain the role of electrical engineers in the development of electricity sources and the products that use electricity.

Educational Standards

Each TeachEngineering lesson or activity is correlated to one or more K-12 science, technology, engineering or math (STEM) educational standards.

All 100,000+ K-12 STEM standards covered in TeachEngineering are collected, maintained and packaged by the Achievement Standards Network (ASN), a project of D2L (www.achievementstandards.org).

In the ASN, standards are hierarchically structured: first by source; e.g., by state; within source by type; e.g., science or mathematics; within type by subtype, then by grade, etc.

NGSS Performance Expectation

Click to view other curriculum aligned to this Performance Expectation

This activity focuses on the following Three Dimensional Learning aspects of NGSS:

Science & Engineering Practices

Disciplinary Core Ideas

Crosscutting Concepts

Make observations to produce data to serve as the basis for evidence for an explanation of a phenomenon or test a design solution.

Energy can be moved from place to place by moving objects or through sound, light, or electric currents. Energy is present whenever there are moving objects, sound, light, or heat. When objects collide, energy can be transferred from one object to another, thereby changing their motion. In such collisions, some energy is typically also transferred to the surrounding air; as a result, the air gets heated and sound is produced. Light also transfers energy from place to place. Energy can also be transferred from place to place by electric currents, which can then be used locally to produce motion, sound, heat, or light. The currents may have been produced to begin with by transforming the energy of motion into electrical energy.

Energy can be transferred in various ways and between objects.

Suggest an alignment not listed above

Materials List

To make a potato battery, each group needs:

3 copper pennies (or copper strips), one per potato

3 zinc nails; these are galvanized nails, available at hardware stores

5 insulated wires, 15-20 cm (6-8 inches) long, with alligator clips at the ends

1 low-current, light emitting diode (LED) clock (or LCD clock) requiring ~1.5 volts (or a small LED)

OR above materials can be purchased cumulatively in a kit, available online

For the entire class to share or one per team:

(optional) multimeter(s) or voltmeter(s); a multimeter measures current, voltage and resistance of a circuit; available at Radio Shack or other electronics stores or websites

Worksheets and Attachments
Visit [www.teachengineering.org/activities/view/cub_energy2_lesson04_activity2] to print or download.

Introduction/Motivation

What is electrical energy? From where does it come? Can you think of anything that needs electrical energy to work? How about lamps, music players, TVs and ovens? How do we get the power to run these devices? What role do electrical engineers play in improving our lives?

One place we can find electrical energy in our homes is at a wall outlet. So, how does electrical energy reach the wall outlet in our house? The energy comes from an electrical power plant, which usually makes electrical energy from burning fossil fuels, such as coal and oil. The heat energy from the burning fuel heats up water. When the water boils, it becomes steam, which flows through a pipe into a turbine (a wheel with blades). As the turbine spins from the steam, it turns a generator (a spinning magnet) that unbalances the charges in nearby atoms and produces a current of electricity. The electrical current flows through protected wires to our house.

How else can we power electrical appliances? That's right, from a battery. A battery works by providing electrons with a solution in which they can move around. Have you ever noticed that some batteries have a copper end that is positive (shown with a plus [+] sign) and another end that is negative (shown with a minus [-] sign)? Zinc is a metal that likes to give its electrons to copper. Usually, zinc just gives its electrons to copper and then the process stops. However, if you provide the electrons with a solution (called an electrolyte) to help them move to the copper, and you give the electrons a wire in which they can move from the copper back to the zinc, you can produce a circuit and a flowing path of electrical energy. (Note: Conventional current flows from positive to negative, so from the copper, through the wire, back to the zinc. The electrons actually flow negative to positive.)

A circuit is a complete path of electrical energy. This means that electrical energy or charge is produced or stored somewhere ( voltage) and has a path for the charge to flow (or current). Another part of a circuit is a resistance, such as a light bulb. Electrical engineers create circuits to help electrical energy perform work, such as lighting a room or keeping food cold. An appliance, light bulb or almost any device that uses electrical energy is a resistance. A resistance prevents or slows an electrical current or charge from moving. When electrical current flows through a source of resistance, it can be changed into light or heat or sound. Even though you cannot see it, the light bulb or appliance slows down the electrical charge.

Electrical engineers help develop the many modern products and appliances that require electrical energy. Electrical engineers also help create the technology used to generate the electrical energy in power plants in the first place. These engineers know a lot about circuits and they continually work to find better ways to store electrical charge and generate electrical current without using nonrenewable fossil fuels such as coal and oil. These electrical engineers are very important in almost everything we do! Essentially, electrical engineers create improvements for society and help save our planet for future generations. Today, we are going to be electrical engineers and learn more about how electrical energy works in a circuit. We are also going to look at generating electrical current from the energy stored in a potato! Do you think we can light a bulb with a potato? Let's try it!

Procedure

Background

How does a potato battery work? The copper (Cu) atoms attract electrons more than the zinc (Zn) atoms. If you place a strip of copper and a strip of zinc in contact with each other, many electrons pass from the zinc to the copper. As they concentrate on the copper, the electrons repel each other. When the force of repulsion between electrons and the force of attraction of electrons to the copper become equalized, the flow of electrons stops. Unfortunately it is not possible to take advantage of this behavior to produce electricity because the flow of charges stops almost immediately. On the other hand, if you bathe the two strips in a conductive solution, and connect them externally with a wire, the reactions between the electrodes and the solution continually furnish the circuit with charges. In this way, the process that produces the electrical energy continues and becomes useful. In a conductive solution, the charge is carried by ions that move through the solution. In the solid state, the ions are not able to move around freely. However, once they are dissolved in water, they become completely mobile. They can "swim" around in the water and thus can respond to an electric current from a battery. That current supplies electrons that cause positive ions to flow in one direction and negative ions to flow in the opposite direction. The ions carry electrical charge from one electrode to another, completing the electrical circuit.

For a conductive solution, use any electrolyte, whether it is an acid, base or salt solution. An electrolyte is a substance whose aqueous solution contains various ions and thus conducts electricity. Therefore, the more free ions a solution has, the better conductor it will be. Many fruits and vegetables contain juices rich in ions and are therefore good electrical conductors.

Like any battery, a potato battery has a limited life span. The electrodes undergo chemical reactions that block the flow of electricity. The electromotive force diminishes and the battery stops working. Usually, what happens is the production of hydrogen at the copper electrode and the zinc electrode acquires deposits of oxides that act as a barrier between the metal and the electrolyte. This is referred to as the electrodes being polarized. To achieve a longer life and higher voltages and current flows, it is necessary to use electrolytes better suited for the purpose. Commercial batteries, apart from their normal electrolyte, contain chemicals with an affinity for hydrogen, which combine with the hydrogen before it can polarize the electrodes.

Before the Activity

With the Students

1. Divide the class into teams of two or three students each. Hand out the materials.

2. Direct groups to carefully place the zinc nails and copper pennies into the potato. Make sure the two different metals do not touch each other in the potato (see Figure 1).

3. Connect one alligator clip to the end of the penny sticking out of the potato and another alligator clip to the end of the nail sticking out of the potato (see Figure 1).

Figure 1. Placement of the nail, penny and alligator clips.

1. (If you have a multimeter) Tell students that a multimeter is an instrument that measures current, voltage and resistance of a circuit, and is a tool (created by and) often used by engineers. Set the multimeter on a low "DC volts" scale for voltage and "DC milliamps" for current, so students can see the charge that one potato can produce. Expect the potato to produce just less than 1 volt. Encourage students to convert the decimal readout from the multimeter to a fraction (for example, 0.82 volts = 82/100 volts).

2. Have the students figure out how many potatoes they need to light their LED clock (or clock). For example, if their potato produces a voltage of 0.8 volts, then they may need two potatoes to power a 1.5 voltage LED.

3. Have students experiment to figure out how to connect two potatoes together. To connect two potatoes in series (to add more voltage), place a penny and nail into a second potato, and connect the wire from the zinc nail in the first potato to the copper penny in the second. Then, add a third wire to the zinc nail in the second potato. Always remember to connect the copper (positive) end of the potato (battery) to the zinc (negative) end of the next potato (see Figure 2).

Figure 2. Activity setup to create a potato battery to power an LED clock.

1. Expect two potatoes in series to be able to light an LED; however, you might need three. Show students how to connect the LEDs to the potato in the correct manner, that is, the positive end of the LED to the negative end of the potato battery (zinc nail) and the negative end of the LED to the positive end of the potato battery (copper penny).

2. Have students discuss how the potatoes provide the electrolyte (solution) for the chemical battery to work. Ask for suggestions of other foods we could try (for example, lemons, berries, apples).

3. Ask students to complete the worksheet either individually or in pairs. After they finish, have them compare answers with a peer or another pair, giving all students time to finish.

Vocabulary/Definitions

conductor: An object that allows the transfer of electrons.

current: The movement of electrons.

electrical energy: Energy produced through the movement of electrons (voltage X current).

electrolyte: A solution that conducts electricity.

energy: The ability to do work.

insulator: An object that inhibits the transfer of electrons.

resistance: Objects or substances that prevent the passage of a steady electric current.

voltage: The amount of energy produced.

Assessment

Pre-Activity Assessment

Brainstorming: In small groups, have students engage in open discussion. Remind them that no idea or suggestion is "silly." All ideas should be respectfully heard. Take an uncritical position, encourage wild ideas and discourage criticism of ideas. Ask students how many items they can think of that run on batteries. As a class, record their ideas on the board.

Quick Poll: Before the activity begins, ask the class a question and tally their responses on the board. Ask: Can we get electrical energy from a fruit or vegetable?

Activity Embedded Assessment

Worksheet /Pairs Check: Have students work individually or in pairs on the Make a Battery Worksheet. After they finish, have them compare answers with a peer or another pair, giving all students time to finish the worksheet.

Hypothesize: Ask each group what would happen if we added more potatoes in a row to our circuits? (Answer: Adding more potatoes in a row is the same as adding batteries in a row. The voltage of each piece of potato is added up. Thus, the voltage of our circuit would increase. On the other hand, the current of our circuit would not increase. Current is not dependent on how many potatoes but is related to the size of each potato individually.)

Post-Activity Assessment

Problem Solving: Present the class with the following math problems and ask students to calculate how many of each vegetable or fruit are needed to light the bulb.

If a lemon produces 1 Volt of energy, how many lemons would you need to light a 2 Volt light bulb? (Answer: 2)

If a potato produces 0.8 Volts of energy, how many potatoes would you need to light a 1.5 Volt light bulb? (Answer: 2)

If a potato produces 0.8 Volts of energy, how many potatoes would you need to light a 3 Volt digital clock? (Answer: 4)

If you have a lemon that produces 1 Volt of energy and an apple that produces 1 Volt of energy, can you light a 3 Volt clock? (Answer: No, you would need one more lemon or apple.)

Diagramming: Engineers must understand how circuits work in order to develop cool new technologies. Draw a picture of your potato battery. Label the battery (voltage) and the resistance (light bulb). Draw an arrow to show the current flow (from the copper end to the zinc end). List two cool products that an engineer could develop that run off a fruit battery.

Troubleshooting Tips

If the LED clock, light or small light bulbs do not work, check the setup of the potato battery. Perhaps the ends are not all connected from negative to positive, or perhaps there is not enough potato voltage. Check the voltage of the potato using a multimeter or voltmeter. Another possibility is having enough voltage, but not enough current to light the bulb, which is why it is recommended to use only very low-volt LED clocks or bulbs. Also, try using more potatoes (i.e., 5 potato halves) to strengthen conductivity. Try different LED colors (for example, the blue LED may work better than the red).

Lemons and oranges also work well for this activity. They work best if you first roll them on a table top, which breaks down the cells inside so more juice flows through the fruit (current).

Some people have more conduction success using copper strips instead of copper pennies (can also wrap the pennies in copper ribbon).

Soaking the potatoes in Gatorade overnight can make them more conductive.

Activity Extensions

At activity end, before students disassemble their potato batteries, it is fun to have the entire class connect their fruit batteries in series, making "a serious tater circle."

Have students try the activity again using different fruits or vegetables! Many fruits and vegetables work, such as lemons, limes, apples and carrots. Have students compare and contrast the performance of different fruits and vegetables.

Have students complete the activity again using an electrolyte solution, such as salt water or vinegar. Have them compare and contrast the performance of different electrolyte solutions.

To add a math component, have students use the multimeter to compare the flow of electricity for several different fruits as well as to the total amount of fruits used. Ask them to graph the results and hypothesize what is happening.

Activity Scaling

Have more advanced students experiment with parallel and series configurations using different numbers of potatoes.

References

Dictionary.com. Lexico Publishing Group, LLC. Accessed September 28, 2005. (Source of some vocabulary definitions, with some adaptation) http://www.dictionary.com

Phillips, W.D. Chapter 2P: Using a Multimeter. Design Electronics (online textbook) DOCTRONICS Educational Publishing, UK. Accessed September 28, 2005. (Good design, technology and electronics resources.) http://www.doctronics.co.uk/meter.htm

Copyright © 2005 by Regents of the University of Colorado

Contributors Sharon D. Perez-Suarez; Jeff Lyng; Malinda Schaefer Zarske; Denise W. Carlson; Janet Yowell

Supporting Program Integrated Teaching and Learning Program, College of Engineering, University of Colorado Boulder

Acknowledgements

The contents of this digital library curriculum were developed under grants from the Fund for the Improvement of Postsecondary Education (FIPSE), U.S. Department of Education, and the National Science Foundation (GK-12 grant no. 0338326). However, these contents do not necessarily represent the policies of the Department of Education or National Science Foundation, and you should not assume endorsement by the federal government.

Last modified: July 9, 2020

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Students use potatoes to light an LED clock (or light bulb) as they learn how a battery works in a simple circuit and how chemical energy changes to electrical energy. As they learn more about electrical energy, they better understand the concepts of voltage, current and resistance.

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I really like the photo scavenger hunt activity because it allows children to use technology and get more familiar with a tool while also learning/practicing a skill. It helps them apply things they've learned in school to real world objects.

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I've wanted to do a photo scavenger hunt with the kids for a long, long time. I always love any kind of scavenger hunt. And the boys love taking photos.

But the boys don't have their own camera, and all I have is my DSLR that I use (affiliate link) and I don't want to hand that over to the boys (I'm nervous of it breaking... and I couldn't go without it until I got it replaced).

I finally realized that the iPad mini (affiliate link) that we have can be used! Duh! It took me forever to come up with this solution.

Even better, it let me put the photo scavenger hunt right on the iPad for the kids to search for and then have George take photos of what he found.

I decided to hunt around the yard to find different shapes of objects. A square, circle, triangle and rectangle.

Triangles were the hardest to find, but found them in spokes of the cars and bikes.

Squares I found in our porch railing and skirting.

Circles were everywhere! I found a bell on their bikes, the ends of hoses, wheels of the million toys we have.

I took about a dozen photos of shapes I found around the yard and stored them in an album on the iPad for George.

George then took the iPad around the yard to find those shapes.

Once he found it, he switched over to the camera app to snap a photo of it too.

I have a collection of both my photos and his photos and its fun to compare the two!

Below is my photo for the triangle (I didn't have the red triangle and text in the photos, I just added that for this post to be clear).

And below is the photo that George took of the triangles he found.

He got the shape and object in every photo. But definitely not the same photo!

Below is my rectangle photo of a brick on the side of our house.

And below is George's version of the rectangle.

He didn't crop up nearly as close (maybe because I've told him time and time again to stay out of my plant beds and he's finally learning to listen).

This is the photo I took of the circle, a bell on his bike.

George tried to get it just the same! He did awesome hunting for them and finding the shapes!

This is his photo of the circle bell.

This photo scavenger hunt for the kids wasn't nearly as daunting as I thought it would be to put together. It took all of five minutes for me to walk around and find the shapes and snap the photos.

George loves anything to do with technology, so using the iPad to go on the scavenger hunt was a winner. Plus he got to take photos which he loves to do with it.

Got a hunter? The kids will love to go on any of these 32 ideas for scavenger hunts!

And in the meantime, he practiced his shapes. Triangles are still tough for him, but he's got squares and rectangles down now!

More move and learn ideas:

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Photo Scavenger Hunt for Kids to Find Shapes

# data[].attributes.attachment_link.description
I've wanted to do a photo scavenger hunt with the kids for a long, long time. I always love any kind of scavenger hunt. And the boys love taking photos. But the boys don't have their own camera, and all I have is my DSLR that I use (affiliate link) and I don't want to hand that over to the boys (I'm nervous of it breaking...

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I think that this is the best lesson because energy and how we get energy is super important and I think that students should understand it because it is happening around us all of the time. It discusses the different types of energy and how each one is created and what it does. I like that it talks about where energy comes from. It is informative but also interesting at the same time.

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With an introduction to the ideas of energy, students discuss specific types of energy and the practical sources of energy. Hands-on activities help them identify types of energy in their surroundings and enhance their understanding of energy.

Educational Standards

Learning Objectives

After this lesson, students should be able to:

Define energy and identify the different types that exist.

Define potential and kinetic energy.

Relate specific types of energy to different engineering projects.

Describe the role of engineering in finding and testing various sources of energy for the production of electricity.

Introduction/Motivation

You cannot always see energy, touch it or hold it in your hand, but energy is everywhere.

Energy is the ability to do work, to make things happen, and to cause changes. Energy cannot be made or destroyed; it can only be changed into different forms. Can you name a form of energy? (Examples: Light, heat, electricity, sound) From where do you think we get electricity? (Possible answers: Power plant, the outlet in the wall, food) Can you think of an example in which energy is changed from one form to another? How about a light bulb? We turn it on by plugging it into the wall. What happens when you leave a light bulb on for a while? It gets hot! Well, that is an example of electrical energy changing into heat energy from the vibration of the filament, which also produces light!

Now, let's think about a gas-fueled electricity plant. A power plant produces electricity by changing the chemical energy in fuel into electrical energy. First, gas is burned within the plant, converting its chemical energy into heat. Next, the heat turns water into steam, which moves a turbine motor or generator. Finally, the generator produces electricity.

This steam-based technology was first discovered in the early 1700s when engineers began to figure out ways to use the energy in steam released by boiling water. They developed engines that converted steam energy into mechanical energy for use in farm and factory machinery, and later for trains and cars. Historians often cite the development of the steam engine as the start of a period in modern history called the industrial revolution.

We classify energy in two ways. First is potential energy, which is the amount of energy something has stored inside it. Anything can have potential energy. A battery has potential energy stored by a difference in ionic concentration; even you have potential energy, as you sit in your chair. How much potential energy you have depends on a few things, including how high up you are and how big you are. Next is kinetic energy. Kinetic energy is the energy of an object in motion. Anything that is moving has kinetic energy. Mechanical objects, such as a clock or a person on a skateboard, have kinetic energy, but so do light, sound, wind and water. Can you see examples of energy around the classroom? Well, today we are going to find some of these examples and learn about how engineers work with different types of energy.

Write the following phrases on the board and discuss with the class.
What is energy?

The ability to do work or cause change.

Work is the application of a force through a distance. (Ask the students for examples, such as moving a box across the room, sweeping, etc.)

- Force can put matter into motion or stop it if it is already moving.

- Motion is a change in position of an object with time.

To do work, energy is needed.
From where does energy come?

Natural energy sources: food, water, plants, trees, gravity, sun, fossil fuels, uranium, plutonium

Ways that humans have harnessed or converted natural energy sources: hydroelectric dams, coal/oil power plants, nuclear power plants, wind turbines, solar panels, etc.

What are different types of energy? (See the Vocabulary / Definitions section.)

Kinetic energy: electrical, light, thermal, solar, sound, wind, hydro

Potential energy: chemical, mechanical, nuclear, gravitational

How do we use energy?

To break down and digest food (in our bodies)

To heat houses and other buildings

To illuminate lights

To power televisions, radios, games, cars

To run computers and appliances

Lesson Background and Concepts for Teachers

Energy takes many forms. Thermal energy (or heat) boils water, keeps us warm and drives engines. Chemical energy fuels automobiles and airplanes. Electrical energy drives many small machines and keeps lights glowing. Almost every form of energy can be converted into other forms. But whatever form it is in, energy is essentially the capacity for making something happen or, as engineers and scientists say, "doing work."

Figure 1. The energy cycle from the sun to our homes.

Nearly all our energy comes to us ultimately from the sun (see Figure 1). We get some energy directly via passive solar lighting and heating, or solar power cells. However, most energy comes indirectly via burning fossil fuels (coal, oil and gas), which received their energy from fossilized plants and other organisms. The plants and organisms originally obtained their energy directly from the sun by a process called photosynthesis. Some of these sources of energy are renewable and others nonrenewable or limited in their available quantity.

Vocabulary/Definitions

biomass energy: An energy resource derived from organic matter. Many people use biomass energy to heat their homes; they burn wood. Many agricultural crops are also biomass. For instance, corn can be fermented to produce ethanol that is burned as a liquid fuel. Wood is a renewable energy source as long as cut trees are replaced immediately.

chemical energy: The energy stored on the chemical bonds of molecules that it released during a chemical reaction. Chemical energy holds molecules together and keeps them from moving apart. For example, a car engine uses chemical energy stored in gasoline, and moving people use chemical energy from food.

electrical energy: Electrical energy exists when charged particles attract or repel each other. Television sets, computers and refrigerators use electrical energy.

energy: The ability to do work.

kinetic energy: The energy of motion. For example, a spinning top, a falling object and a rolling ball all have kinetic energy. The motion, if resisted by a force, does work. Wind and water both have kinetic energy.

light energy: Visible light energy, such as from a light bulb or fireflies or stars, is just one form of electromagnetic energy. Others forms include infrared and ultraviolet light.

mechanical energy: Mechanical energy is energy that can be used to do work. It is the sum of an object's kinetic and potential energy.

nonrenewable energy: Energy from sources that are used faster than they can be created. Sources include oil (petroleum), natural gas, coal and uranium (nuclear).

nuclear energy: Nuclear energy is the energy found inside the nucleus of atoms and can only be released when atoms are split. Some power companies that supply homes, schools and buildings with electricity use nuclear energy to generate electricity.

potential energy: Potential energy is the energy stored by an object as a result of its position. A roller coaster at the top of a hill has potential energy.

renewable energy: Energy that is made from sources that can be regenerated. Sources include solar, wind, geothermal, biomass, ocean and hydro (water).

sound energy: Audible energy that is released when you talk, play musical instruments or slam a door.

thermal energy: Heat energy produced when the molecules of a substance vibrate. The more heat a substance has, the more rapid the vibration of its molecules. Heat energy flows from places of higher temperature to places of lower temperature.

Associated Activities

What Is Energy? Short Demos - In three short demonstrations, students learn about some of the forms of energy commonly found around us.

Energy Detectives at Work - Students become engineering detectives and find examples of energy all around the classroom or school.

Lesson Closure

Today we started learning about energy and engineering. Can you define and describe the word "energy?" What types of energy can you see, feel or hear? (Possible answers: Heat, light, sound, movement.) Why would an engineer care about energy? (Answer: Engineers develop products that use energy. Engineers help develop ways to store energy for our use.)

Assign students the attached Energy Vocabulary Quiz to gauge their mastery in understanding the uses of energy in their surroundings and the fundamental types of energy.

Attachments

Assessment

Pre-Lesson Assessment

Discussion: Ask the students the following questions:

What is energy? (Possible answers: The ability to do work or cause change and the capacity for vigorous activity. Work is the application of a force through a distance [ask for examples]. Force can put matter into motion or stop it if it is already moving. Motion is a change in position of an object with time. To do work, energy is needed.)

Where does energy come from? (Answers: Power plants, people, food, light, windmills, turbines, fires, etc.)

What are different types of energy? (Answers: Chemical, thermal, mechanical, potential, kinetic, solar, sound, nuclear, etc. [see the Vocabulary / Definitions section].)

How do we use energy? (Possible answers: Our bodies use energy to break down and digest food. We use energy to heat houses and buildings, to turn on lights, to power televisions, radios, cars, computers, appliances, etc. Sound energy is used in communication and to find fish in the ocean!)

Post-Introduction Assessment

Take-Home Definitions: Ask students to ask several members of their families for definitions of a specific energy form, and then look up the definition in the dictionary. Have them write down comparisons of these definitions and a reason why each might be different. Share these explanations with the class.

Lesson Summary Assessment

Energy Identifier: Bring to class examples or images of the following objects. Have students identify the type of energy that is related to each item. You could set up stations around the room or turn it into a game in which the students earn points for each type of energy correctly identified.

Fan (Answer: Uses electrical energy; produces kinetic energy.)

Battery (Answer: Stores chemical energy.)

Banana (Answer: A source of chemical energy.)

Flashlight (Answer: Uses chemical energy; produces light energy.)

Radio (Answer: Uses electrical energy; produces sound energy.)

Guitar (Answer: Uses chemical energy from a person [energy from the food they eat]; produces sound energy.)

Candle (Answer: Uses chemical energy; produces light and thermal energy.)

Waterfall (Answer: The water has potential energy at the top of the falls and kinetic energy at the bottom of the falls.)

Vocabulary Review: Assign students the attached Energy Vocabulary Quiz to gauge their understanding of the ways energy is used in their surroundings and the fundamental types of energy.

Lesson Extension Activities

Have students research the source of your local utility company's electricity. Is it coal, natural gas, hydro, nuclear, wind or some combination? Many local utility companies provide detailed websites and extensive K-12 outreach programs for schools. A representative may even come to your classroom or lead a field trip.

For students with a high reading comprehension, use the attached Energy Vocabulary Worksheet to reinforce their understanding of the material.

References

Consumer Energy Center, California Energy Commission. Accessed September 14, 2005. (information on energy efficiency, alternative fuel vehicles, renewable energy) http://www.consumerenergycenter.org/index.html

Energy Kid's Page. Energy Information Administration, U.S. Department of Energy. Accessed September 14, 2005. ( energy facts, fun & games, energy history, classroom activities) http://www.eia.doe.gov/kids/

Energy Quest: Kid's Page. Updated 2004. California Energy Commission. Accessed September 14, 2005. (Fun, interactive website for kids and teachers) http://www.energyquest.ca.gov/index.html

Graham, I., Taylor, B, Farndon, J. and Oxlade, C. Science Encyclopedia, 1999, pp. 78-90.

Science Projects. Updated March 14, 2005. Energy Quest: Kid's Page, California Energy Commission. Accessed September 14, 2005. (science projects and energy activities for K-12 students) http://www.energyquest.ca.gov/projects/index.html

Contributors Sharon D. Perez-Suarez; Natalie Mach; Malinda Schaefer Zarske; Denise W. Carlson

Copyright © 2005 by Regents of the University of Colorado

Supporting Program Integrated Teaching and Learning Program, College of Engineering, University of Colorado Boulder

Acknowledgements

The contents of this digital library curriculum were developed under grants from the Fund for the Improvement of Postsecondary Education (FIPSE), U.S. Department of Education and National Science Foundation GK-12 (grant no. DGE 0338326). However, these contents do not necessarily represent the policies of the Department of Education or National Science Foundation, and you should not assume endorsement by the federal government.

Last modified: March 20, 2017

# data[].attributes.attachment_link.description
With an introduction to the ideas of energy, students discuss specific types of energy and the practical sources of energy. Hands-on activities help them identify types of energy in their surroundings and enhance their understanding of energy. Educational Standards After this lesson, students should be able to: Define energy and identify the different types that exist.

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I chose the photo scavenger hunt because it can be used for almost any grade. Children get to strengthen their success with technology as well as shapes.

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I've wanted to do a photo scavenger hunt with the kids for a long, long time. I always love any kind of scavenger hunt. And the boys love taking photos.

But the boys don't have their own camera, and all I have is my DSLR that I use (affiliate link) and I don't want to hand that over to the boys (I'm nervous of it breaking... and I couldn't go without it until I got it replaced).

I finally realized that the iPad mini (affiliate link) that we have can be used! Duh! It took me forever to come up with this solution.

Even better, it let me put the photo scavenger hunt right on the iPad for the kids to search for and then have George take photos of what he found.

I decided to hunt around the yard to find different shapes of objects. A square, circle, triangle and rectangle.

Triangles were the hardest to find, but found them in spokes of the cars and bikes.

Squares I found in our porch railing and skirting.

Circles were everywhere! I found a bell on their bikes, the ends of hoses, wheels of the million toys we have.

I took about a dozen photos of shapes I found around the yard and stored them in an album on the iPad for George.

George then took the iPad around the yard to find those shapes.

Once he found it, he switched over to the camera app to snap a photo of it too.

I have a collection of both my photos and his photos and its fun to compare the two!

Below is my photo for the triangle (I didn't have the red triangle and text in the photos, I just added that for this post to be clear).

And below is the photo that George took of the triangles he found.

He got the shape and object in every photo. But definitely not the same photo!

Below is my rectangle photo of a brick on the side of our house.

And below is George's version of the rectangle.

He didn't crop up nearly as close (maybe because I've told him time and time again to stay out of my plant beds and he's finally learning to listen).

This is the photo I took of the circle, a bell on his bike.

George tried to get it just the same! He did awesome hunting for them and finding the shapes!

This is his photo of the circle bell.

This photo scavenger hunt for the kids wasn't nearly as daunting as I thought it would be to put together. It took all of five minutes for me to walk around and find the shapes and snap the photos.

George loves anything to do with technology, so using the iPad to go on the scavenger hunt was a winner. Plus he got to take photos which he loves to do with it.

Got a hunter? The kids will love to go on any of these 32 ideas for scavenger hunts!

And in the meantime, he practiced his shapes. Triangles are still tough for him, but he's got squares and rectangles down now!

More move and learn ideas:

# data[].attributes.attachment_link.title
Photo Scavenger Hunt for Kids to Find Shapes

# data[].attributes.attachment_link.description
I've wanted to do a photo scavenger hunt with the kids for a long, long time. I always love any kind of scavenger hunt. And the boys love taking photos. But the boys don't have their own camera, and all I have is my DSLR that I use (affiliate link) and I don't want to hand that over to the boys (I'm nervous of it breaking...

# data[].attributes.body
This lesson seems like it would be very interesting for the younger ages to complete. They would be able to use the technology provided for them and learn their shapes at the same time. This is a fun and simple way to get the students involved. -Kenzie Bullock

# data[].attributes.attachment_link.readable_text
I've wanted to do a photo scavenger hunt with the kids for a long, long time. I always love any kind of scavenger hunt. And the boys love taking photos.

But the boys don't have their own camera, and all I have is my DSLR that I use (affiliate link) and I don't want to hand that over to the boys (I'm nervous of it breaking... and I couldn't go without it until I got it replaced).

I finally realized that the iPad mini (affiliate link) that we have can be used! Duh! It took me forever to come up with this solution.

Even better, it let me put the photo scavenger hunt right on the iPad for the kids to search for and then have George take photos of what he found.

I decided to hunt around the yard to find different shapes of objects. A square, circle, triangle and rectangle.

Triangles were the hardest to find, but found them in spokes of the cars and bikes.

Squares I found in our porch railing and skirting.

Circles were everywhere! I found a bell on their bikes, the ends of hoses, wheels of the million toys we have.

I took about a dozen photos of shapes I found around the yard and stored them in an album on the iPad for George.

George then took the iPad around the yard to find those shapes.

Once he found it, he switched over to the camera app to snap a photo of it too.

I have a collection of both my photos and his photos and its fun to compare the two!

Below is my photo for the triangle (I didn't have the red triangle and text in the photos, I just added that for this post to be clear).

And below is the photo that George took of the triangles he found.

He got the shape and object in every photo. But definitely not the same photo!

Below is my rectangle photo of a brick on the side of our house.

And below is George's version of the rectangle.

He didn't crop up nearly as close (maybe because I've told him time and time again to stay out of my plant beds and he's finally learning to listen).

This is the photo I took of the circle, a bell on his bike.

George tried to get it just the same! He did awesome hunting for them and finding the shapes!

This is his photo of the circle bell.

This photo scavenger hunt for the kids wasn't nearly as daunting as I thought it would be to put together. It took all of five minutes for me to walk around and find the shapes and snap the photos.

George loves anything to do with technology, so using the iPad to go on the scavenger hunt was a winner. Plus he got to take photos which he loves to do with it.

Got a hunter? The kids will love to go on any of these 32 ideas for scavenger hunts!

And in the meantime, he practiced his shapes. Triangles are still tough for him, but he's got squares and rectangles down now!

More move and learn ideas:

# data[].attributes.attachment_link.title
Photo Scavenger Hunt for Kids to Find Shapes

# data[].attributes.attachment_link.description
I've wanted to do a photo scavenger hunt with the kids for a long, long time. I always love any kind of scavenger hunt. And the boys love taking photos. But the boys don't have their own camera, and all I have is my DSLR that I use (affiliate link) and I don't want to hand that over to the boys (I'm nervous of it breaking...

# data[].attributes.body
I think this lesson would be lots of fun for kids because it incorporates the iPad and gives them the chance to see shapes in everyday objects. I definitely think the children could work together to collaborate or do this individually to help them learn their shapes. It is definitely geared more towards pre-k/kindergarten, but would be very beneficial for these children.

# data[].attributes.attachment_link.readable_text
I've wanted to do a photo scavenger hunt with the kids for a long, long time. I always love any kind of scavenger hunt. And the boys love taking photos.

But the boys don't have their own camera, and all I have is my DSLR that I use (affiliate link) and I don't want to hand that over to the boys (I'm nervous of it breaking... and I couldn't go without it until I got it replaced).

I finally realized that the iPad mini (affiliate link) that we have can be used! Duh! It took me forever to come up with this solution.

Even better, it let me put the photo scavenger hunt right on the iPad for the kids to search for and then have George take photos of what he found.

I decided to hunt around the yard to find different shapes of objects. A square, circle, triangle and rectangle.

Triangles were the hardest to find, but found them in spokes of the cars and bikes.

Squares I found in our porch railing and skirting.

Circles were everywhere! I found a bell on their bikes, the ends of hoses, wheels of the million toys we have.

I took about a dozen photos of shapes I found around the yard and stored them in an album on the iPad for George.

George then took the iPad around the yard to find those shapes.

Once he found it, he switched over to the camera app to snap a photo of it too.

I have a collection of both my photos and his photos and its fun to compare the two!

Below is my photo for the triangle (I didn't have the red triangle and text in the photos, I just added that for this post to be clear).

And below is the photo that George took of the triangles he found.

He got the shape and object in every photo. But definitely not the same photo!

Below is my rectangle photo of a brick on the side of our house.

And below is George's version of the rectangle.

He didn't crop up nearly as close (maybe because I've told him time and time again to stay out of my plant beds and he's finally learning to listen).

This is the photo I took of the circle, a bell on his bike.

George tried to get it just the same! He did awesome hunting for them and finding the shapes!

This is his photo of the circle bell.

This photo scavenger hunt for the kids wasn't nearly as daunting as I thought it would be to put together. It took all of five minutes for me to walk around and find the shapes and snap the photos.

George loves anything to do with technology, so using the iPad to go on the scavenger hunt was a winner. Plus he got to take photos which he loves to do with it.

Got a hunter? The kids will love to go on any of these 32 ideas for scavenger hunts!

And in the meantime, he practiced his shapes. Triangles are still tough for him, but he's got squares and rectangles down now!

More move and learn ideas:

# data[].attributes.attachment_link.title
Photo Scavenger Hunt for Kids to Find Shapes

# data[].attributes.attachment_link.description
I've wanted to do a photo scavenger hunt with the kids for a long, long time. I always love any kind of scavenger hunt. And the boys love taking photos. But the boys don't have their own camera, and all I have is my DSLR that I use (affiliate link) and I don't want to hand that over to the boys (I'm nervous of it breaking...

# data[].attributes.body
I liked this lesson because I feel like it incorporates a lot of the 21st century skills. It is also a fun lesson because it shows students that something simple, like a potato, has the ability to create and operate something cool. It seems like a relatively simple lesson, but would be very fun for students.
- Rachel Achey

# data[].attributes.attachment_link.readable_text
Quick Look

Grade Level: 4 (3-5)

Time Required: 45 minutes

Expendable Cost/Group: US $2.00

Group Size: 3

Activity Dependency: None

Subject Areas: Physical Science, Science and Technology

NGSS Performance Expectations:

Summary Students use potatoes to light an LED clock (or light bulb) as they learn how a battery works in a simple circuit and how chemical energy changes to electrical energy. As they learn more about electrical energy, they better understand the concepts of voltage, current and resistance.
This engineering curriculum aligns to Next Generation Science Standards (NGSS).

Engineering Connection

Engineers use batteries to store energy in a wide range of situations. A solid electrolyte battery is most suitable in very extreme weather conditions, while nickel-zinc batteries work best in electric vehicles. Energy engineers continually evolve technology to improve the performance and life-cycle costs of batteries that store solar and wind energy. When designing a battery, engineers keep in mind the needs of the application, and use different substances to create current flow. They consider characteristics such as power output, ability to recharge, reliability, size, safety, heat generation, length of life cycle, abuse tolerance, cost and ability to be recycled. Isn't the power of engineering creativity amazing?

Learning Objectives

After this activity, students should be able to:

Describe the flow of electrical energy through a simple circuit.

Explain why a light bulb may take more than one battery to light up.

Explain the role of electrical engineers in the development of electricity sources and the products that use electricity.

Educational Standards

Each TeachEngineering lesson or activity is correlated to one or more K-12 science, technology, engineering or math (STEM) educational standards.

All 100,000+ K-12 STEM standards covered in TeachEngineering are collected, maintained and packaged by the Achievement Standards Network (ASN), a project of D2L (www.achievementstandards.org).

In the ASN, standards are hierarchically structured: first by source; e.g., by state; within source by type; e.g., science or mathematics; within type by subtype, then by grade, etc.

NGSS Performance Expectation

Click to view other curriculum aligned to this Performance Expectation

This activity focuses on the following Three Dimensional Learning aspects of NGSS:

Science & Engineering Practices

Disciplinary Core Ideas

Crosscutting Concepts

Make observations to produce data to serve as the basis for evidence for an explanation of a phenomenon or test a design solution.

Energy can be moved from place to place by moving objects or through sound, light, or electric currents. Energy is present whenever there are moving objects, sound, light, or heat. When objects collide, energy can be transferred from one object to another, thereby changing their motion. In such collisions, some energy is typically also transferred to the surrounding air; as a result, the air gets heated and sound is produced. Light also transfers energy from place to place. Energy can also be transferred from place to place by electric currents, which can then be used locally to produce motion, sound, heat, or light. The currents may have been produced to begin with by transforming the energy of motion into electrical energy.

Energy can be transferred in various ways and between objects.

Suggest an alignment not listed above

Materials List

To make a potato battery, each group needs:

3 copper pennies (or copper strips), one per potato

3 zinc nails; these are galvanized nails, available at hardware stores

5 insulated wires, 15-20 cm (6-8 inches) long, with alligator clips at the ends

1 low-current, light emitting diode (LED) clock (or LCD clock) requiring ~1.5 volts (or a small LED)

OR above materials can be purchased cumulatively in a kit, available online

For the entire class to share or one per team:

(optional) multimeter(s) or voltmeter(s); a multimeter measures current, voltage and resistance of a circuit; available at Radio Shack or other electronics stores or websites

Worksheets and Attachments
Visit [www.teachengineering.org/activities/view/cub_energy2_lesson04_activity2] to print or download.

Introduction/Motivation

What is electrical energy? From where does it come? Can you think of anything that needs electrical energy to work? How about lamps, music players, TVs and ovens? How do we get the power to run these devices? What role do electrical engineers play in improving our lives?

One place we can find electrical energy in our homes is at a wall outlet. So, how does electrical energy reach the wall outlet in our house? The energy comes from an electrical power plant, which usually makes electrical energy from burning fossil fuels, such as coal and oil. The heat energy from the burning fuel heats up water. When the water boils, it becomes steam, which flows through a pipe into a turbine (a wheel with blades). As the turbine spins from the steam, it turns a generator (a spinning magnet) that unbalances the charges in nearby atoms and produces a current of electricity. The electrical current flows through protected wires to our house.

How else can we power electrical appliances? That's right, from a battery. A battery works by providing electrons with a solution in which they can move around. Have you ever noticed that some batteries have a copper end that is positive (shown with a plus [+] sign) and another end that is negative (shown with a minus [-] sign)? Zinc is a metal that likes to give its electrons to copper. Usually, zinc just gives its electrons to copper and then the process stops. However, if you provide the electrons with a solution (called an electrolyte) to help them move to the copper, and you give the electrons a wire in which they can move from the copper back to the zinc, you can produce a circuit and a flowing path of electrical energy. (Note: Conventional current flows from positive to negative, so from the copper, through the wire, back to the zinc. The electrons actually flow negative to positive.)

A circuit is a complete path of electrical energy. This means that electrical energy or charge is produced or stored somewhere ( voltage) and has a path for the charge to flow (or current). Another part of a circuit is a resistance, such as a light bulb. Electrical engineers create circuits to help electrical energy perform work, such as lighting a room or keeping food cold. An appliance, light bulb or almost any device that uses electrical energy is a resistance. A resistance prevents or slows an electrical current or charge from moving. When electrical current flows through a source of resistance, it can be changed into light or heat or sound. Even though you cannot see it, the light bulb or appliance slows down the electrical charge.

Electrical engineers help develop the many modern products and appliances that require electrical energy. Electrical engineers also help create the technology used to generate the electrical energy in power plants in the first place. These engineers know a lot about circuits and they continually work to find better ways to store electrical charge and generate electrical current without using nonrenewable fossil fuels such as coal and oil. These electrical engineers are very important in almost everything we do! Essentially, electrical engineers create improvements for society and help save our planet for future generations. Today, we are going to be electrical engineers and learn more about how electrical energy works in a circuit. We are also going to look at generating electrical current from the energy stored in a potato! Do you think we can light a bulb with a potato? Let's try it!

Procedure

Background

How does a potato battery work? The copper (Cu) atoms attract electrons more than the zinc (Zn) atoms. If you place a strip of copper and a strip of zinc in contact with each other, many electrons pass from the zinc to the copper. As they concentrate on the copper, the electrons repel each other. When the force of repulsion between electrons and the force of attraction of electrons to the copper become equalized, the flow of electrons stops. Unfortunately it is not possible to take advantage of this behavior to produce electricity because the flow of charges stops almost immediately. On the other hand, if you bathe the two strips in a conductive solution, and connect them externally with a wire, the reactions between the electrodes and the solution continually furnish the circuit with charges. In this way, the process that produces the electrical energy continues and becomes useful. In a conductive solution, the charge is carried by ions that move through the solution. In the solid state, the ions are not able to move around freely. However, once they are dissolved in water, they become completely mobile. They can "swim" around in the water and thus can respond to an electric current from a battery. That current supplies electrons that cause positive ions to flow in one direction and negative ions to flow in the opposite direction. The ions carry electrical charge from one electrode to another, completing the electrical circuit.

For a conductive solution, use any electrolyte, whether it is an acid, base or salt solution. An electrolyte is a substance whose aqueous solution contains various ions and thus conducts electricity. Therefore, the more free ions a solution has, the better conductor it will be. Many fruits and vegetables contain juices rich in ions and are therefore good electrical conductors.

Like any battery, a potato battery has a limited life span. The electrodes undergo chemical reactions that block the flow of electricity. The electromotive force diminishes and the battery stops working. Usually, what happens is the production of hydrogen at the copper electrode and the zinc electrode acquires deposits of oxides that act as a barrier between the metal and the electrolyte. This is referred to as the electrodes being polarized. To achieve a longer life and higher voltages and current flows, it is necessary to use electrolytes better suited for the purpose. Commercial batteries, apart from their normal electrolyte, contain chemicals with an affinity for hydrogen, which combine with the hydrogen before it can polarize the electrodes.

Before the Activity

With the Students

1. Divide the class into teams of two or three students each. Hand out the materials.

2. Direct groups to carefully place the zinc nails and copper pennies into the potato. Make sure the two different metals do not touch each other in the potato (see Figure 1).

3. Connect one alligator clip to the end of the penny sticking out of the potato and another alligator clip to the end of the nail sticking out of the potato (see Figure 1).

Figure 1. Placement of the nail, penny and alligator clips.

1. (If you have a multimeter) Tell students that a multimeter is an instrument that measures current, voltage and resistance of a circuit, and is a tool (created by and) often used by engineers. Set the multimeter on a low "DC volts" scale for voltage and "DC milliamps" for current, so students can see the charge that one potato can produce. Expect the potato to produce just less than 1 volt. Encourage students to convert the decimal readout from the multimeter to a fraction (for example, 0.82 volts = 82/100 volts).

2. Have the students figure out how many potatoes they need to light their LED clock (or clock). For example, if their potato produces a voltage of 0.8 volts, then they may need two potatoes to power a 1.5 voltage LED.

3. Have students experiment to figure out how to connect two potatoes together. To connect two potatoes in series (to add more voltage), place a penny and nail into a second potato, and connect the wire from the zinc nail in the first potato to the copper penny in the second. Then, add a third wire to the zinc nail in the second potato. Always remember to connect the copper (positive) end of the potato (battery) to the zinc (negative) end of the next potato (see Figure 2).

Figure 2. Activity setup to create a potato battery to power an LED clock.

1. Expect two potatoes in series to be able to light an LED; however, you might need three. Show students how to connect the LEDs to the potato in the correct manner, that is, the positive end of the LED to the negative end of the potato battery (zinc nail) and the negative end of the LED to the positive end of the potato battery (copper penny).

2. Have students discuss how the potatoes provide the electrolyte (solution) for the chemical battery to work. Ask for suggestions of other foods we could try (for example, lemons, berries, apples).

3. Ask students to complete the worksheet either individually or in pairs. After they finish, have them compare answers with a peer or another pair, giving all students time to finish.

Vocabulary/Definitions

conductor: An object that allows the transfer of electrons.

current: The movement of electrons.

electrical energy: Energy produced through the movement of electrons (voltage X current).

electrolyte: A solution that conducts electricity.

energy: The ability to do work.

insulator: An object that inhibits the transfer of electrons.

resistance: Objects or substances that prevent the passage of a steady electric current.

voltage: The amount of energy produced.

Assessment

Pre-Activity Assessment

Brainstorming: In small groups, have students engage in open discussion. Remind them that no idea or suggestion is "silly." All ideas should be respectfully heard. Take an uncritical position, encourage wild ideas and discourage criticism of ideas. Ask students how many items they can think of that run on batteries. As a class, record their ideas on the board.

Quick Poll: Before the activity begins, ask the class a question and tally their responses on the board. Ask: Can we get electrical energy from a fruit or vegetable?

Activity Embedded Assessment

Worksheet /Pairs Check: Have students work individually or in pairs on the Make a Battery Worksheet. After they finish, have them compare answers with a peer or another pair, giving all students time to finish the worksheet.

Hypothesize: Ask each group what would happen if we added more potatoes in a row to our circuits? (Answer: Adding more potatoes in a row is the same as adding batteries in a row. The voltage of each piece of potato is added up. Thus, the voltage of our circuit would increase. On the other hand, the current of our circuit would not increase. Current is not dependent on how many potatoes but is related to the size of each potato individually.)

Post-Activity Assessment

Problem Solving: Present the class with the following math problems and ask students to calculate how many of each vegetable or fruit are needed to light the bulb.

If a lemon produces 1 Volt of energy, how many lemons would you need to light a 2 Volt light bulb? (Answer: 2)

If a potato produces 0.8 Volts of energy, how many potatoes would you need to light a 1.5 Volt light bulb? (Answer: 2)

If a potato produces 0.8 Volts of energy, how many potatoes would you need to light a 3 Volt digital clock? (Answer: 4)

If you have a lemon that produces 1 Volt of energy and an apple that produces 1 Volt of energy, can you light a 3 Volt clock? (Answer: No, you would need one more lemon or apple.)

Diagramming: Engineers must understand how circuits work in order to develop cool new technologies. Draw a picture of your potato battery. Label the battery (voltage) and the resistance (light bulb). Draw an arrow to show the current flow (from the copper end to the zinc end). List two cool products that an engineer could develop that run off a fruit battery.

Troubleshooting Tips

If the LED clock, light or small light bulbs do not work, check the setup of the potato battery. Perhaps the ends are not all connected from negative to positive, or perhaps there is not enough potato voltage. Check the voltage of the potato using a multimeter or voltmeter. Another possibility is having enough voltage, but not enough current to light the bulb, which is why it is recommended to use only very low-volt LED clocks or bulbs. Also, try using more potatoes (i.e., 5 potato halves) to strengthen conductivity. Try different LED colors (for example, the blue LED may work better than the red).

Lemons and oranges also work well for this activity. They work best if you first roll them on a table top, which breaks down the cells inside so more juice flows through the fruit (current).

Some people have more conduction success using copper strips instead of copper pennies (can also wrap the pennies in copper ribbon).

Soaking the potatoes in Gatorade overnight can make them more conductive.

Activity Extensions

At activity end, before students disassemble their potato batteries, it is fun to have the entire class connect their fruit batteries in series, making "a serious tater circle."

Have students try the activity again using different fruits or vegetables! Many fruits and vegetables work, such as lemons, limes, apples and carrots. Have students compare and contrast the performance of different fruits and vegetables.

Have students complete the activity again using an electrolyte solution, such as salt water or vinegar. Have them compare and contrast the performance of different electrolyte solutions.

To add a math component, have students use the multimeter to compare the flow of electricity for several different fruits as well as to the total amount of fruits used. Ask them to graph the results and hypothesize what is happening.

Activity Scaling

Have more advanced students experiment with parallel and series configurations using different numbers of potatoes.

References

Dictionary.com. Lexico Publishing Group, LLC. Accessed September 28, 2005. (Source of some vocabulary definitions, with some adaptation) http://www.dictionary.com

Phillips, W.D. Chapter 2P: Using a Multimeter. Design Electronics (online textbook) DOCTRONICS Educational Publishing, UK. Accessed September 28, 2005. (Good design, technology and electronics resources.) http://www.doctronics.co.uk/meter.htm

Copyright © 2005 by Regents of the University of Colorado

Contributors Sharon D. Perez-Suarez; Jeff Lyng; Malinda Schaefer Zarske; Denise W. Carlson; Janet Yowell

Supporting Program Integrated Teaching and Learning Program, College of Engineering, University of Colorado Boulder

Acknowledgements

The contents of this digital library curriculum were developed under grants from the Fund for the Improvement of Postsecondary Education (FIPSE), U.S. Department of Education, and the National Science Foundation (GK-12 grant no. 0338326). However, these contents do not necessarily represent the policies of the Department of Education or National Science Foundation, and you should not assume endorsement by the federal government.

Last modified: July 9, 2020

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Students use potatoes to light an LED clock (or light bulb) as they learn how a battery works in a simple circuit and how chemical energy changes to electrical energy. As they learn more about electrical energy, they better understand the concepts of voltage, current and resistance.

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I really like the potato power lesson because

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Tiffany Blose
This lesson does not require that many materials. If a child has a chance to fling something they will definitely want to do it. This lesson also covers a lot of math and science standards.

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Posted on by ASEE

(Lesson Courtesy COSI Columbus - The Center for Science and Industry). Level: Grades 4 - 8. Time required: 30 to 50 minutes. Click HERE for PDF of activity. Click HERE for version developed by Ohio State University engineering graduate students and Maize Elementary teachers

Overview

This simple catapult activity for students in grades 4 - 8 teaches them how energy is transferred when a plastic spoon is pulled back, then released, rocketing its payload - a single marshmallow.

Background

What's going on? The plastic spoon has an inherent elasticity, which means it will return to its original shape after being deformed. Rubber bands and other elastic objects also have this property. When the spoon is deformed, the force used to cause that deformation is "stored" in the spoon as elastic potential energy. When the spoon is released, the elastic potential energy changes to kinetic energy as the spoon returns to its original shape, carrying the marshmallow along with it. The marshmallow continues to move after the spoon has stopped due to its inertia.

Catapult Information

(from the Museum of Ancient Inventions, Smith College)

The catapult was an ancient siege machine that could hurl heavy objects or shoot arrows with great force and for considerable distances. Some catapults could throw stones weighing as much as 350 pounds for distances greater than 300 feet.

The Greek Dionysius the Elder of Syracuse, who was looking to develop a new type of weapon, invented the catapult about 400 BCE. Thereafter, it became a key weapon in warfare and remained so up through mediaeval times. Two major catapults evolved from Dionysius's invention: the double-armed machine, or ballista, used for shooting arrows, and the single-armed catapult designed for hurling large objects. Although the Romans added wheels to both types of catapult for maneuverability, very little in the design of the machine changed.The reconstruction shown here is of a single-armed stone-hurling catapult, approximately two feet long and one-and-a-half feet tall. Its hurling arm is driven by a cocked, winch-pulled cord.

Standards (Ohio)

Physical Science: 1.6, 3.3, 3.4, 7.2, 7.4

Vocabulary

elasticity, potential energy, kinetic energy, deflection angle

Materials

Plastic spoon

1-2 bags of miniature marshmallows

marking pens

tape measure or meter stick

masking tape

protractor

safety goggles

Procedure
Instruction for teachers:
Set up the classroom so that you have at least 20 feet of open space in front of the launching area for a landing area. Have students put on goggles, then align teams of 3-4 students along one side of a set of long tables or a counter so the catapults will be aimed across the room.

Distribute to each group safety goggles, spoons, marshmallows, protractors, and lengths of masking tape.
Instructions for students:
1. Prepare your catapult by taping a spoon firmly against the edge of a table, perpendicular to the tabletop with the bowl of the spoon facing toward the table.

2. Mark your marshmallows for identification with a pen, using your group initials.

3. Test the setup of your catapult and marshmallow: Hold the marshmallow in the bowl of the spoon. Use your thumb to help anchor the spoon handle against the table.

4. Practice launch: Keeping the end of the spoon handle against the table, launching the marshmallow across the room. (Don't point it at anyone!)

5. Experiment with pulling the spoon back farther to change the angle - what are the results?

Now, determine the best deflection angle - how far you pull back the spoon - to launch the marshmallow the farthest possible distance. Decide how much to deflect the spoon, using a protractor to measure the angle between the spoon and the table. Record the measurements of your deflection angle on a sheet of paper, then launch your marshmallow and measure the distance it travels. Repeat this two more times and compute the average of the three.

6. Now, change the deflection angle of the catapult and repeat. Record the average distance for three separate different catapult angles. Record your results. What angle between the spoon and table launches the marshmallow the farthest?

7. Based on your data, predict the optimum deflection angle.

8. Hold a class contest to find out who can make a marshmallow fly the farthest.

Extensions

Ask the class what would happen if they changed the weight/size of the marshmallow - and how could they do that? Which other techniques could makes the marshmallow go farther? Higher?

Spoons may be made of several different types of plastic. Bring in other plastic spoons and try this experiment. Compare and contrast the results. Look up the properties of the different types of plastic and relate these properties to the results.

For homework, challenge students to come up with their own catapult design - still using the marshmallow load - then allow them to construct, test, and demonstrate their models in class the next day. What innovative solutions did each group devise? Have students evaluate their results and those of their classmates.

Assign students to research the history of catapults. When were they used, and for what purposes?

Resources

More ancient inventions at Smith College's online Museum of Ancient Inventions
http://www.middle-ages.org.uk/catapults.htm http://www.medieval-castle-siege-weapons.com/medieval-catapults.html
Filed under: Class Activities, Grades 6-8, Grades K-5, Grades K-5, Lesson Plans

Tags: catapult, Class Activities, forces and motion, Fun & Games, Grades 4 - 8, Grades K-5, Newton's Laws, Physical Science, Physics, trebuchet

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eGFI - For Teachers " Activity: Catapult Marshmallow Launch

# data[].attributes.attachment_link.description
Posted on by ASEE (Lesson Courtesy COSI Columbus - The Center for Science and Industry). Level: Grades 4 - 8. Time required: 30 to 50 minutes. Click HERE for PDF of activity.

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I chose potato power because students don't go to school expecting to make power come from a potato. Its something the students will be engaged in all the way throughout the lesson.

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Quick Look

Grade Level: 4 (3-5)

Time Required: 45 minutes

Expendable Cost/Group: US $2.00

Group Size: 3

Activity Dependency: None

Subject Areas: Physical Science, Science and Technology

NGSS Performance Expectations:

Summary Students use potatoes to light an LED clock (or light bulb) as they learn how a battery works in a simple circuit and how chemical energy changes to electrical energy. As they learn more about electrical energy, they better understand the concepts of voltage, current and resistance.
This engineering curriculum aligns to Next Generation Science Standards (NGSS).

Engineering Connection

Engineers use batteries to store energy in a wide range of situations. A solid electrolyte battery is most suitable in very extreme weather conditions, while nickel-zinc batteries work best in electric vehicles. Energy engineers continually evolve technology to improve the performance and life-cycle costs of batteries that store solar and wind energy. When designing a battery, engineers keep in mind the needs of the application, and use different substances to create current flow. They consider characteristics such as power output, ability to recharge, reliability, size, safety, heat generation, length of life cycle, abuse tolerance, cost and ability to be recycled. Isn't the power of engineering creativity amazing?

Learning Objectives

After this activity, students should be able to:

Describe the flow of electrical energy through a simple circuit.

Explain why a light bulb may take more than one battery to light up.

Explain the role of electrical engineers in the development of electricity sources and the products that use electricity.

Educational Standards

Each TeachEngineering lesson or activity is correlated to one or more K-12 science, technology, engineering or math (STEM) educational standards.

All 100,000+ K-12 STEM standards covered in TeachEngineering are collected, maintained and packaged by the Achievement Standards Network (ASN), a project of D2L (www.achievementstandards.org).

In the ASN, standards are hierarchically structured: first by source; e.g., by state; within source by type; e.g., science or mathematics; within type by subtype, then by grade, etc.

NGSS Performance Expectation

Click to view other curriculum aligned to this Performance Expectation

This activity focuses on the following Three Dimensional Learning aspects of NGSS:

Science & Engineering Practices

Disciplinary Core Ideas

Crosscutting Concepts

Make observations to produce data to serve as the basis for evidence for an explanation of a phenomenon or test a design solution.

Energy can be moved from place to place by moving objects or through sound, light, or electric currents. Energy is present whenever there are moving objects, sound, light, or heat. When objects collide, energy can be transferred from one object to another, thereby changing their motion. In such collisions, some energy is typically also transferred to the surrounding air; as a result, the air gets heated and sound is produced. Light also transfers energy from place to place. Energy can also be transferred from place to place by electric currents, which can then be used locally to produce motion, sound, heat, or light. The currents may have been produced to begin with by transforming the energy of motion into electrical energy.

Energy can be transferred in various ways and between objects.

Suggest an alignment not listed above

Materials List

To make a potato battery, each group needs:

3 copper pennies (or copper strips), one per potato

3 zinc nails; these are galvanized nails, available at hardware stores

5 insulated wires, 15-20 cm (6-8 inches) long, with alligator clips at the ends

1 low-current, light emitting diode (LED) clock (or LCD clock) requiring ~1.5 volts (or a small LED)

OR above materials can be purchased cumulatively in a kit, available online

For the entire class to share or one per team:

(optional) multimeter(s) or voltmeter(s); a multimeter measures current, voltage and resistance of a circuit; available at Radio Shack or other electronics stores or websites

Worksheets and Attachments
Visit [www.teachengineering.org/activities/view/cub_energy2_lesson04_activity2] to print or download.

Introduction/Motivation

What is electrical energy? From where does it come? Can you think of anything that needs electrical energy to work? How about lamps, music players, TVs and ovens? How do we get the power to run these devices? What role do electrical engineers play in improving our lives?

One place we can find electrical energy in our homes is at a wall outlet. So, how does electrical energy reach the wall outlet in our house? The energy comes from an electrical power plant, which usually makes electrical energy from burning fossil fuels, such as coal and oil. The heat energy from the burning fuel heats up water. When the water boils, it becomes steam, which flows through a pipe into a turbine (a wheel with blades). As the turbine spins from the steam, it turns a generator (a spinning magnet) that unbalances the charges in nearby atoms and produces a current of electricity. The electrical current flows through protected wires to our house.

How else can we power electrical appliances? That's right, from a battery. A battery works by providing electrons with a solution in which they can move around. Have you ever noticed that some batteries have a copper end that is positive (shown with a plus [+] sign) and another end that is negative (shown with a minus [-] sign)? Zinc is a metal that likes to give its electrons to copper. Usually, zinc just gives its electrons to copper and then the process stops. However, if you provide the electrons with a solution (called an electrolyte) to help them move to the copper, and you give the electrons a wire in which they can move from the copper back to the zinc, you can produce a circuit and a flowing path of electrical energy. (Note: Conventional current flows from positive to negative, so from the copper, through the wire, back to the zinc. The electrons actually flow negative to positive.)

A circuit is a complete path of electrical energy. This means that electrical energy or charge is produced or stored somewhere ( voltage) and has a path for the charge to flow (or current). Another part of a circuit is a resistance, such as a light bulb. Electrical engineers create circuits to help electrical energy perform work, such as lighting a room or keeping food cold. An appliance, light bulb or almost any device that uses electrical energy is a resistance. A resistance prevents or slows an electrical current or charge from moving. When electrical current flows through a source of resistance, it can be changed into light or heat or sound. Even though you cannot see it, the light bulb or appliance slows down the electrical charge.

Electrical engineers help develop the many modern products and appliances that require electrical energy. Electrical engineers also help create the technology used to generate the electrical energy in power plants in the first place. These engineers know a lot about circuits and they continually work to find better ways to store electrical charge and generate electrical current without using nonrenewable fossil fuels such as coal and oil. These electrical engineers are very important in almost everything we do! Essentially, electrical engineers create improvements for society and help save our planet for future generations. Today, we are going to be electrical engineers and learn more about how electrical energy works in a circuit. We are also going to look at generating electrical current from the energy stored in a potato! Do you think we can light a bulb with a potato? Let's try it!

Procedure

Background

How does a potato battery work? The copper (Cu) atoms attract electrons more than the zinc (Zn) atoms. If you place a strip of copper and a strip of zinc in contact with each other, many electrons pass from the zinc to the copper. As they concentrate on the copper, the electrons repel each other. When the force of repulsion between electrons and the force of attraction of electrons to the copper become equalized, the flow of electrons stops. Unfortunately it is not possible to take advantage of this behavior to produce electricity because the flow of charges stops almost immediately. On the other hand, if you bathe the two strips in a conductive solution, and connect them externally with a wire, the reactions between the electrodes and the solution continually furnish the circuit with charges. In this way, the process that produces the electrical energy continues and becomes useful. In a conductive solution, the charge is carried by ions that move through the solution. In the solid state, the ions are not able to move around freely. However, once they are dissolved in water, they become completely mobile. They can "swim" around in the water and thus can respond to an electric current from a battery. That current supplies electrons that cause positive ions to flow in one direction and negative ions to flow in the opposite direction. The ions carry electrical charge from one electrode to another, completing the electrical circuit.

For a conductive solution, use any electrolyte, whether it is an acid, base or salt solution. An electrolyte is a substance whose aqueous solution contains various ions and thus conducts electricity. Therefore, the more free ions a solution has, the better conductor it will be. Many fruits and vegetables contain juices rich in ions and are therefore good electrical conductors.

Like any battery, a potato battery has a limited life span. The electrodes undergo chemical reactions that block the flow of electricity. The electromotive force diminishes and the battery stops working. Usually, what happens is the production of hydrogen at the copper electrode and the zinc electrode acquires deposits of oxides that act as a barrier between the metal and the electrolyte. This is referred to as the electrodes being polarized. To achieve a longer life and higher voltages and current flows, it is necessary to use electrolytes better suited for the purpose. Commercial batteries, apart from their normal electrolyte, contain chemicals with an affinity for hydrogen, which combine with the hydrogen before it can polarize the electrodes.

Before the Activity

With the Students

1. Divide the class into teams of two or three students each. Hand out the materials.

2. Direct groups to carefully place the zinc nails and copper pennies into the potato. Make sure the two different metals do not touch each other in the potato (see Figure 1).

3. Connect one alligator clip to the end of the penny sticking out of the potato and another alligator clip to the end of the nail sticking out of the potato (see Figure 1).

Figure 1. Placement of the nail, penny and alligator clips.

1. (If you have a multimeter) Tell students that a multimeter is an instrument that measures current, voltage and resistance of a circuit, and is a tool (created by and) often used by engineers. Set the multimeter on a low "DC volts" scale for voltage and "DC milliamps" for current, so students can see the charge that one potato can produce. Expect the potato to produce just less than 1 volt. Encourage students to convert the decimal readout from the multimeter to a fraction (for example, 0.82 volts = 82/100 volts).

2. Have the students figure out how many potatoes they need to light their LED clock (or clock). For example, if their potato produces a voltage of 0.8 volts, then they may need two potatoes to power a 1.5 voltage LED.

3. Have students experiment to figure out how to connect two potatoes together. To connect two potatoes in series (to add more voltage), place a penny and nail into a second potato, and connect the wire from the zinc nail in the first potato to the copper penny in the second. Then, add a third wire to the zinc nail in the second potato. Always remember to connect the copper (positive) end of the potato (battery) to the zinc (negative) end of the next potato (see Figure 2).

Figure 2. Activity setup to create a potato battery to power an LED clock.

1. Expect two potatoes in series to be able to light an LED; however, you might need three. Show students how to connect the LEDs to the potato in the correct manner, that is, the positive end of the LED to the negative end of the potato battery (zinc nail) and the negative end of the LED to the positive end of the potato battery (copper penny).

2. Have students discuss how the potatoes provide the electrolyte (solution) for the chemical battery to work. Ask for suggestions of other foods we could try (for example, lemons, berries, apples).

3. Ask students to complete the worksheet either individually or in pairs. After they finish, have them compare answers with a peer or another pair, giving all students time to finish.

Vocabulary/Definitions

conductor: An object that allows the transfer of electrons.

current: The movement of electrons.

electrical energy: Energy produced through the movement of electrons (voltage X current).

electrolyte: A solution that conducts electricity.

energy: The ability to do work.

insulator: An object that inhibits the transfer of electrons.

resistance: Objects or substances that prevent the passage of a steady electric current.

voltage: The amount of energy produced.

Assessment

Pre-Activity Assessment

Brainstorming: In small groups, have students engage in open discussion. Remind them that no idea or suggestion is "silly." All ideas should be respectfully heard. Take an uncritical position, encourage wild ideas and discourage criticism of ideas. Ask students how many items they can think of that run on batteries. As a class, record their ideas on the board.

Quick Poll: Before the activity begins, ask the class a question and tally their responses on the board. Ask: Can we get electrical energy from a fruit or vegetable?

Activity Embedded Assessment

Worksheet /Pairs Check: Have students work individually or in pairs on the Make a Battery Worksheet. After they finish, have them compare answers with a peer or another pair, giving all students time to finish the worksheet.

Hypothesize: Ask each group what would happen if we added more potatoes in a row to our circuits? (Answer: Adding more potatoes in a row is the same as adding batteries in a row. The voltage of each piece of potato is added up. Thus, the voltage of our circuit would increase. On the other hand, the current of our circuit would not increase. Current is not dependent on how many potatoes but is related to the size of each potato individually.)

Post-Activity Assessment

Problem Solving: Present the class with the following math problems and ask students to calculate how many of each vegetable or fruit are needed to light the bulb.

If a lemon produces 1 Volt of energy, how many lemons would you need to light a 2 Volt light bulb? (Answer: 2)

If a potato produces 0.8 Volts of energy, how many potatoes would you need to light a 1.5 Volt light bulb? (Answer: 2)

If a potato produces 0.8 Volts of energy, how many potatoes would you need to light a 3 Volt digital clock? (Answer: 4)

If you have a lemon that produces 1 Volt of energy and an apple that produces 1 Volt of energy, can you light a 3 Volt clock? (Answer: No, you would need one more lemon or apple.)

Diagramming: Engineers must understand how circuits work in order to develop cool new technologies. Draw a picture of your potato battery. Label the battery (voltage) and the resistance (light bulb). Draw an arrow to show the current flow (from the copper end to the zinc end). List two cool products that an engineer could develop that run off a fruit battery.

Troubleshooting Tips

If the LED clock, light or small light bulbs do not work, check the setup of the potato battery. Perhaps the ends are not all connected from negative to positive, or perhaps there is not enough potato voltage. Check the voltage of the potato using a multimeter or voltmeter. Another possibility is having enough voltage, but not enough current to light the bulb, which is why it is recommended to use only very low-volt LED clocks or bulbs. Also, try using more potatoes (i.e., 5 potato halves) to strengthen conductivity. Try different LED colors (for example, the blue LED may work better than the red).

Lemons and oranges also work well for this activity. They work best if you first roll them on a table top, which breaks down the cells inside so more juice flows through the fruit (current).

Some people have more conduction success using copper strips instead of copper pennies (can also wrap the pennies in copper ribbon).

Soaking the potatoes in Gatorade overnight can make them more conductive.

Activity Extensions

At activity end, before students disassemble their potato batteries, it is fun to have the entire class connect their fruit batteries in series, making "a serious tater circle."

Have students try the activity again using different fruits or vegetables! Many fruits and vegetables work, such as lemons, limes, apples and carrots. Have students compare and contrast the performance of different fruits and vegetables.

Have students complete the activity again using an electrolyte solution, such as salt water or vinegar. Have them compare and contrast the performance of different electrolyte solutions.

To add a math component, have students use the multimeter to compare the flow of electricity for several different fruits as well as to the total amount of fruits used. Ask them to graph the results and hypothesize what is happening.

Activity Scaling

Have more advanced students experiment with parallel and series configurations using different numbers of potatoes.

References

Dictionary.com. Lexico Publishing Group, LLC. Accessed September 28, 2005. (Source of some vocabulary definitions, with some adaptation) http://www.dictionary.com

Phillips, W.D. Chapter 2P: Using a Multimeter. Design Electronics (online textbook) DOCTRONICS Educational Publishing, UK. Accessed September 28, 2005. (Good design, technology and electronics resources.) http://www.doctronics.co.uk/meter.htm

Copyright © 2005 by Regents of the University of Colorado

Contributors Sharon D. Perez-Suarez; Jeff Lyng; Malinda Schaefer Zarske; Denise W. Carlson; Janet Yowell

Supporting Program Integrated Teaching and Learning Program, College of Engineering, University of Colorado Boulder

Acknowledgements

The contents of this digital library curriculum were developed under grants from the Fund for the Improvement of Postsecondary Education (FIPSE), U.S. Department of Education, and the National Science Foundation (GK-12 grant no. 0338326). However, these contents do not necessarily represent the policies of the Department of Education or National Science Foundation, and you should not assume endorsement by the federal government.

Last modified: July 9, 2020

# data[].attributes.attachment_link.description
Students use potatoes to light an LED clock (or light bulb) as they learn how a battery works in a simple circuit and how chemical energy changes to electrical energy. As they learn more about electrical energy, they better understand the concepts of voltage, current and resistance.

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I like the marshmallow catapult lesson the best because it is the most fun and it allows students to be creative and productive! It also calls for some trial and error which will help students problem solve and think critically.

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This lesson seems like it could be more intriguing for the students. They'd be able to see a variety of ways on how energy is produced. They also can learn about the importance of certain things in nature to make plants grow. -Kenzie Bullock

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Quick Look

Grade Level: 4 (3-5)

Time Required: 45 minutes

Expendable Cost/Group: US $2.00

Group Size: 3

Activity Dependency: None

Subject Areas: Physical Science, Science and Technology

NGSS Performance Expectations:

Summary Students use potatoes to light an LED clock (or light bulb) as they learn how a battery works in a simple circuit and how chemical energy changes to electrical energy. As they learn more about electrical energy, they better understand the concepts of voltage, current and resistance.
This engineering curriculum aligns to Next Generation Science Standards (NGSS).

Engineering Connection

Engineers use batteries to store energy in a wide range of situations. A solid electrolyte battery is most suitable in very extreme weather conditions, while nickel-zinc batteries work best in electric vehicles. Energy engineers continually evolve technology to improve the performance and life-cycle costs of batteries that store solar and wind energy. When designing a battery, engineers keep in mind the needs of the application, and use different substances to create current flow. They consider characteristics such as power output, ability to recharge, reliability, size, safety, heat generation, length of life cycle, abuse tolerance, cost and ability to be recycled. Isn't the power of engineering creativity amazing?

Learning Objectives

After this activity, students should be able to:

Describe the flow of electrical energy through a simple circuit.

Explain why a light bulb may take more than one battery to light up.

Explain the role of electrical engineers in the development of electricity sources and the products that use electricity.

Educational Standards

Each TeachEngineering lesson or activity is correlated to one or more K-12 science, technology, engineering or math (STEM) educational standards.

All 100,000+ K-12 STEM standards covered in TeachEngineering are collected, maintained and packaged by the Achievement Standards Network (ASN), a project of D2L (www.achievementstandards.org).

In the ASN, standards are hierarchically structured: first by source; e.g., by state; within source by type; e.g., science or mathematics; within type by subtype, then by grade, etc.

NGSS Performance Expectation

Click to view other curriculum aligned to this Performance Expectation

This activity focuses on the following Three Dimensional Learning aspects of NGSS:

Science & Engineering Practices

Disciplinary Core Ideas

Crosscutting Concepts

Make observations to produce data to serve as the basis for evidence for an explanation of a phenomenon or test a design solution.

Energy can be moved from place to place by moving objects or through sound, light, or electric currents. Energy is present whenever there are moving objects, sound, light, or heat. When objects collide, energy can be transferred from one object to another, thereby changing their motion. In such collisions, some energy is typically also transferred to the surrounding air; as a result, the air gets heated and sound is produced. Light also transfers energy from place to place. Energy can also be transferred from place to place by electric currents, which can then be used locally to produce motion, sound, heat, or light. The currents may have been produced to begin with by transforming the energy of motion into electrical energy.

Energy can be transferred in various ways and between objects.

Suggest an alignment not listed above

Materials List

To make a potato battery, each group needs:

3 copper pennies (or copper strips), one per potato

3 zinc nails; these are galvanized nails, available at hardware stores

5 insulated wires, 15-20 cm (6-8 inches) long, with alligator clips at the ends

1 low-current, light emitting diode (LED) clock (or LCD clock) requiring ~1.5 volts (or a small LED)

OR above materials can be purchased cumulatively in a kit, available online

For the entire class to share or one per team:

(optional) multimeter(s) or voltmeter(s); a multimeter measures current, voltage and resistance of a circuit; available at Radio Shack or other electronics stores or websites

Worksheets and Attachments
Visit [www.teachengineering.org/activities/view/cub_energy2_lesson04_activity2] to print or download.

Introduction/Motivation

What is electrical energy? From where does it come? Can you think of anything that needs electrical energy to work? How about lamps, music players, TVs and ovens? How do we get the power to run these devices? What role do electrical engineers play in improving our lives?

One place we can find electrical energy in our homes is at a wall outlet. So, how does electrical energy reach the wall outlet in our house? The energy comes from an electrical power plant, which usually makes electrical energy from burning fossil fuels, such as coal and oil. The heat energy from the burning fuel heats up water. When the water boils, it becomes steam, which flows through a pipe into a turbine (a wheel with blades). As the turbine spins from the steam, it turns a generator (a spinning magnet) that unbalances the charges in nearby atoms and produces a current of electricity. The electrical current flows through protected wires to our house.

How else can we power electrical appliances? That's right, from a battery. A battery works by providing electrons with a solution in which they can move around. Have you ever noticed that some batteries have a copper end that is positive (shown with a plus [+] sign) and another end that is negative (shown with a minus [-] sign)? Zinc is a metal that likes to give its electrons to copper. Usually, zinc just gives its electrons to copper and then the process stops. However, if you provide the electrons with a solution (called an electrolyte) to help them move to the copper, and you give the electrons a wire in which they can move from the copper back to the zinc, you can produce a circuit and a flowing path of electrical energy. (Note: Conventional current flows from positive to negative, so from the copper, through the wire, back to the zinc. The electrons actually flow negative to positive.)

A circuit is a complete path of electrical energy. This means that electrical energy or charge is produced or stored somewhere ( voltage) and has a path for the charge to flow (or current). Another part of a circuit is a resistance, such as a light bulb. Electrical engineers create circuits to help electrical energy perform work, such as lighting a room or keeping food cold. An appliance, light bulb or almost any device that uses electrical energy is a resistance. A resistance prevents or slows an electrical current or charge from moving. When electrical current flows through a source of resistance, it can be changed into light or heat or sound. Even though you cannot see it, the light bulb or appliance slows down the electrical charge.

Electrical engineers help develop the many modern products and appliances that require electrical energy. Electrical engineers also help create the technology used to generate the electrical energy in power plants in the first place. These engineers know a lot about circuits and they continually work to find better ways to store electrical charge and generate electrical current without using nonrenewable fossil fuels such as coal and oil. These electrical engineers are very important in almost everything we do! Essentially, electrical engineers create improvements for society and help save our planet for future generations. Today, we are going to be electrical engineers and learn more about how electrical energy works in a circuit. We are also going to look at generating electrical current from the energy stored in a potato! Do you think we can light a bulb with a potato? Let's try it!

Procedure

Background

How does a potato battery work? The copper (Cu) atoms attract electrons more than the zinc (Zn) atoms. If you place a strip of copper and a strip of zinc in contact with each other, many electrons pass from the zinc to the copper. As they concentrate on the copper, the electrons repel each other. When the force of repulsion between electrons and the force of attraction of electrons to the copper become equalized, the flow of electrons stops. Unfortunately it is not possible to take advantage of this behavior to produce electricity because the flow of charges stops almost immediately. On the other hand, if you bathe the two strips in a conductive solution, and connect them externally with a wire, the reactions between the electrodes and the solution continually furnish the circuit with charges. In this way, the process that produces the electrical energy continues and becomes useful. In a conductive solution, the charge is carried by ions that move through the solution. In the solid state, the ions are not able to move around freely. However, once they are dissolved in water, they become completely mobile. They can "swim" around in the water and thus can respond to an electric current from a battery. That current supplies electrons that cause positive ions to flow in one direction and negative ions to flow in the opposite direction. The ions carry electrical charge from one electrode to another, completing the electrical circuit.

For a conductive solution, use any electrolyte, whether it is an acid, base or salt solution. An electrolyte is a substance whose aqueous solution contains various ions and thus conducts electricity. Therefore, the more free ions a solution has, the better conductor it will be. Many fruits and vegetables contain juices rich in ions and are therefore good electrical conductors.

Like any battery, a potato battery has a limited life span. The electrodes undergo chemical reactions that block the flow of electricity. The electromotive force diminishes and the battery stops working. Usually, what happens is the production of hydrogen at the copper electrode and the zinc electrode acquires deposits of oxides that act as a barrier between the metal and the electrolyte. This is referred to as the electrodes being polarized. To achieve a longer life and higher voltages and current flows, it is necessary to use electrolytes better suited for the purpose. Commercial batteries, apart from their normal electrolyte, contain chemicals with an affinity for hydrogen, which combine with the hydrogen before it can polarize the electrodes.

Before the Activity

With the Students

1. Divide the class into teams of two or three students each. Hand out the materials.

2. Direct groups to carefully place the zinc nails and copper pennies into the potato. Make sure the two different metals do not touch each other in the potato (see Figure 1).

3. Connect one alligator clip to the end of the penny sticking out of the potato and another alligator clip to the end of the nail sticking out of the potato (see Figure 1).

Figure 1. Placement of the nail, penny and alligator clips.

1. (If you have a multimeter) Tell students that a multimeter is an instrument that measures current, voltage and resistance of a circuit, and is a tool (created by and) often used by engineers. Set the multimeter on a low "DC volts" scale for voltage and "DC milliamps" for current, so students can see the charge that one potato can produce. Expect the potato to produce just less than 1 volt. Encourage students to convert the decimal readout from the multimeter to a fraction (for example, 0.82 volts = 82/100 volts).

2. Have the students figure out how many potatoes they need to light their LED clock (or clock). For example, if their potato produces a voltage of 0.8 volts, then they may need two potatoes to power a 1.5 voltage LED.

3. Have students experiment to figure out how to connect two potatoes together. To connect two potatoes in series (to add more voltage), place a penny and nail into a second potato, and connect the wire from the zinc nail in the first potato to the copper penny in the second. Then, add a third wire to the zinc nail in the second potato. Always remember to connect the copper (positive) end of the potato (battery) to the zinc (negative) end of the next potato (see Figure 2).

Figure 2. Activity setup to create a potato battery to power an LED clock.

1. Expect two potatoes in series to be able to light an LED; however, you might need three. Show students how to connect the LEDs to the potato in the correct manner, that is, the positive end of the LED to the negative end of the potato battery (zinc nail) and the negative end of the LED to the positive end of the potato battery (copper penny).

2. Have students discuss how the potatoes provide the electrolyte (solution) for the chemical battery to work. Ask for suggestions of other foods we could try (for example, lemons, berries, apples).

3. Ask students to complete the worksheet either individually or in pairs. After they finish, have them compare answers with a peer or another pair, giving all students time to finish.

Vocabulary/Definitions

conductor: An object that allows the transfer of electrons.

current: The movement of electrons.

electrical energy: Energy produced through the movement of electrons (voltage X current).

electrolyte: A solution that conducts electricity.

energy: The ability to do work.

insulator: An object that inhibits the transfer of electrons.

resistance: Objects or substances that prevent the passage of a steady electric current.

voltage: The amount of energy produced.

Assessment

Pre-Activity Assessment

Brainstorming: In small groups, have students engage in open discussion. Remind them that no idea or suggestion is "silly." All ideas should be respectfully heard. Take an uncritical position, encourage wild ideas and discourage criticism of ideas. Ask students how many items they can think of that run on batteries. As a class, record their ideas on the board.

Quick Poll: Before the activity begins, ask the class a question and tally their responses on the board. Ask: Can we get electrical energy from a fruit or vegetable?

Activity Embedded Assessment

Worksheet /Pairs Check: Have students work individually or in pairs on the Make a Battery Worksheet. After they finish, have them compare answers with a peer or another pair, giving all students time to finish the worksheet.

Hypothesize: Ask each group what would happen if we added more potatoes in a row to our circuits? (Answer: Adding more potatoes in a row is the same as adding batteries in a row. The voltage of each piece of potato is added up. Thus, the voltage of our circuit would increase. On the other hand, the current of our circuit would not increase. Current is not dependent on how many potatoes but is related to the size of each potato individually.)

Post-Activity Assessment

Problem Solving: Present the class with the following math problems and ask students to calculate how many of each vegetable or fruit are needed to light the bulb.

If a lemon produces 1 Volt of energy, how many lemons would you need to light a 2 Volt light bulb? (Answer: 2)

If a potato produces 0.8 Volts of energy, how many potatoes would you need to light a 1.5 Volt light bulb? (Answer: 2)

If a potato produces 0.8 Volts of energy, how many potatoes would you need to light a 3 Volt digital clock? (Answer: 4)

If you have a lemon that produces 1 Volt of energy and an apple that produces 1 Volt of energy, can you light a 3 Volt clock? (Answer: No, you would need one more lemon or apple.)

Diagramming: Engineers must understand how circuits work in order to develop cool new technologies. Draw a picture of your potato battery. Label the battery (voltage) and the resistance (light bulb). Draw an arrow to show the current flow (from the copper end to the zinc end). List two cool products that an engineer could develop that run off a fruit battery.

Troubleshooting Tips

If the LED clock, light or small light bulbs do not work, check the setup of the potato battery. Perhaps the ends are not all connected from negative to positive, or perhaps there is not enough potato voltage. Check the voltage of the potato using a multimeter or voltmeter. Another possibility is having enough voltage, but not enough current to light the bulb, which is why it is recommended to use only very low-volt LED clocks or bulbs. Also, try using more potatoes (i.e., 5 potato halves) to strengthen conductivity. Try different LED colors (for example, the blue LED may work better than the red).

Lemons and oranges also work well for this activity. They work best if you first roll them on a table top, which breaks down the cells inside so more juice flows through the fruit (current).

Some people have more conduction success using copper strips instead of copper pennies (can also wrap the pennies in copper ribbon).

Soaking the potatoes in Gatorade overnight can make them more conductive.

Activity Extensions

At activity end, before students disassemble their potato batteries, it is fun to have the entire class connect their fruit batteries in series, making "a serious tater circle."

Have students try the activity again using different fruits or vegetables! Many fruits and vegetables work, such as lemons, limes, apples and carrots. Have students compare and contrast the performance of different fruits and vegetables.

Have students complete the activity again using an electrolyte solution, such as salt water or vinegar. Have them compare and contrast the performance of different electrolyte solutions.

To add a math component, have students use the multimeter to compare the flow of electricity for several different fruits as well as to the total amount of fruits used. Ask them to graph the results and hypothesize what is happening.

Activity Scaling

Have more advanced students experiment with parallel and series configurations using different numbers of potatoes.

References

Dictionary.com. Lexico Publishing Group, LLC. Accessed September 28, 2005. (Source of some vocabulary definitions, with some adaptation) http://www.dictionary.com

Phillips, W.D. Chapter 2P: Using a Multimeter. Design Electronics (online textbook) DOCTRONICS Educational Publishing, UK. Accessed September 28, 2005. (Good design, technology and electronics resources.) http://www.doctronics.co.uk/meter.htm

Copyright © 2005 by Regents of the University of Colorado

Contributors Sharon D. Perez-Suarez; Jeff Lyng; Malinda Schaefer Zarske; Denise W. Carlson; Janet Yowell

Supporting Program Integrated Teaching and Learning Program, College of Engineering, University of Colorado Boulder

Acknowledgements

The contents of this digital library curriculum were developed under grants from the Fund for the Improvement of Postsecondary Education (FIPSE), U.S. Department of Education, and the National Science Foundation (GK-12 grant no. 0338326). However, these contents do not necessarily represent the policies of the Department of Education or National Science Foundation, and you should not assume endorsement by the federal government.

Last modified: July 9, 2020

# data[].attributes.attachment_link.description
Students use potatoes to light an LED clock (or light bulb) as they learn how a battery works in a simple circuit and how chemical energy changes to electrical energy. As they learn more about electrical energy, they better understand the concepts of voltage, current and resistance.

# data[].attributes.body
I think that the marshmallow catapult is the best one. It is fun, informative, and engaging. It is challenging, but I also think that because it is fun, that the kids will be really intrigued and into it. They will learn a lot because they will find it fun.

# data[].attributes.attachment_link.readable_text
Posted on by ASEE

(Lesson Courtesy COSI Columbus - The Center for Science and Industry). Level: Grades 4 - 8. Time required: 30 to 50 minutes. Click HERE for PDF of activity. Click HERE for version developed by Ohio State University engineering graduate students and Maize Elementary teachers

Overview

This simple catapult activity for students in grades 4 - 8 teaches them how energy is transferred when a plastic spoon is pulled back, then released, rocketing its payload - a single marshmallow.

Background

What's going on? The plastic spoon has an inherent elasticity, which means it will return to its original shape after being deformed. Rubber bands and other elastic objects also have this property. When the spoon is deformed, the force used to cause that deformation is "stored" in the spoon as elastic potential energy. When the spoon is released, the elastic potential energy changes to kinetic energy as the spoon returns to its original shape, carrying the marshmallow along with it. The marshmallow continues to move after the spoon has stopped due to its inertia.

Catapult Information

(from the Museum of Ancient Inventions, Smith College)

The catapult was an ancient siege machine that could hurl heavy objects or shoot arrows with great force and for considerable distances. Some catapults could throw stones weighing as much as 350 pounds for distances greater than 300 feet.

The Greek Dionysius the Elder of Syracuse, who was looking to develop a new type of weapon, invented the catapult about 400 BCE. Thereafter, it became a key weapon in warfare and remained so up through mediaeval times. Two major catapults evolved from Dionysius's invention: the double-armed machine, or ballista, used for shooting arrows, and the single-armed catapult designed for hurling large objects. Although the Romans added wheels to both types of catapult for maneuverability, very little in the design of the machine changed.The reconstruction shown here is of a single-armed stone-hurling catapult, approximately two feet long and one-and-a-half feet tall. Its hurling arm is driven by a cocked, winch-pulled cord.

Standards (Ohio)

Physical Science: 1.6, 3.3, 3.4, 7.2, 7.4

Vocabulary

elasticity, potential energy, kinetic energy, deflection angle

Materials

Plastic spoon

1-2 bags of miniature marshmallows

marking pens

tape measure or meter stick

masking tape

protractor

safety goggles

Procedure
Instruction for teachers:
Set up the classroom so that you have at least 20 feet of open space in front of the launching area for a landing area. Have students put on goggles, then align teams of 3-4 students along one side of a set of long tables or a counter so the catapults will be aimed across the room.

Distribute to each group safety goggles, spoons, marshmallows, protractors, and lengths of masking tape.
Instructions for students:
1. Prepare your catapult by taping a spoon firmly against the edge of a table, perpendicular to the tabletop with the bowl of the spoon facing toward the table.

2. Mark your marshmallows for identification with a pen, using your group initials.

3. Test the setup of your catapult and marshmallow: Hold the marshmallow in the bowl of the spoon. Use your thumb to help anchor the spoon handle against the table.

4. Practice launch: Keeping the end of the spoon handle against the table, launching the marshmallow across the room. (Don't point it at anyone!)

5. Experiment with pulling the spoon back farther to change the angle - what are the results?

Now, determine the best deflection angle - how far you pull back the spoon - to launch the marshmallow the farthest possible distance. Decide how much to deflect the spoon, using a protractor to measure the angle between the spoon and the table. Record the measurements of your deflection angle on a sheet of paper, then launch your marshmallow and measure the distance it travels. Repeat this two more times and compute the average of the three.

6. Now, change the deflection angle of the catapult and repeat. Record the average distance for three separate different catapult angles. Record your results. What angle between the spoon and table launches the marshmallow the farthest?

7. Based on your data, predict the optimum deflection angle.

8. Hold a class contest to find out who can make a marshmallow fly the farthest.

Extensions

Ask the class what would happen if they changed the weight/size of the marshmallow - and how could they do that? Which other techniques could makes the marshmallow go farther? Higher?

Spoons may be made of several different types of plastic. Bring in other plastic spoons and try this experiment. Compare and contrast the results. Look up the properties of the different types of plastic and relate these properties to the results.

For homework, challenge students to come up with their own catapult design - still using the marshmallow load - then allow them to construct, test, and demonstrate their models in class the next day. What innovative solutions did each group devise? Have students evaluate their results and those of their classmates.

Assign students to research the history of catapults. When were they used, and for what purposes?

Resources

More ancient inventions at Smith College's online Museum of Ancient Inventions
http://www.middle-ages.org.uk/catapults.htm http://www.medieval-castle-siege-weapons.com/medieval-catapults.html
Filed under: Class Activities, Grades 6-8, Grades K-5, Grades K-5, Lesson Plans

Tags: catapult, Class Activities, forces and motion, Fun & Games, Grades 4 - 8, Grades K-5, Newton's Laws, Physical Science, Physics, trebuchet

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eGFI - For Teachers " Activity: Catapult Marshmallow Launch

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Posted on by ASEE (Lesson Courtesy COSI Columbus - The Center for Science and Industry). Level: Grades 4 - 8. Time required: 30 to 50 minutes. Click HERE for PDF of activity.

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Tiffany Blose
I chose this lesson because it is something you can do at home or in the classroom. If you tell a student that they can make their own toys they definitely will.

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Make plastic from milk? It seems like some sort of lactose intolerant horror story, but it's actually a really cool science process. Create your own toys, beads, jewelry, and more, with ingredients you have right now in your kitchen. It's so easy and super cool!

Turn Milk Into Plastic Toys!
Disclaimer: This article may contain commission or affiliate links. As an Amazon Associate I earn from qualifying purchases.
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Also known as casein plastic, this process has been used for over 100 years and is the way they used to make plastics before 1945 when synthetic plastics were introduced. Even royalty wore jewelry made from milk plastic many years ago. How cool is that?

With this simple process you can make toys, beads, jewelry, decorative pieces and more. This is a great, budget friendly experiment, with spectacular results that will have your students pumped with excitement for science!

A stove top or microwave to warm the milk
Milk (we used 2%, lower fat content is better)
White Vinegar or Lemon Juice
Bowl
Spoon
Strainer (or can create your own using cheese cloth or similar)
Paper towel
Molds (we loved using our Lego minifigures and Dinosaur molds) or other tools for shaping.

Time: 30 to 90 minutes for the experiment, then 2 days for drying. Add in a little extra time for painting once dry!

Measure out 1 cup of milk (you can also use chocolate milk and the end result smells amazing!), this makes about 4 minifigures or 4 dinosaurs. Heat on the stove top in a pot or in the microwave in a heat resistant bowl. You want it to just start steaming. Remove from the heat. Add 4 tsp of vinegar or lemon juice and stir gently.

The amount of vinegar is not exact. We used 4 tbsp by accident and it was fine, just made for a more intense vinegar smell!

You will notice that it immediately begins to curdle. You're making curds and whey!

Stir gently for approximately one minute for the full reaction to finish and all the curds to form. Don't stir aggressively. Be gentle.

Strain off the whey using a strainer or you can use cheese cloth (or similar). Let drip for a few minutes until most of the liquid has drained off. Gently smoosh the curds around in the strainer if needed.

Now remove the curds and place them on a few layers of paper towel. Carefully pat and squish to remove more liquid. You may need to replace the paper towel and repeat a few times. The goal is to remove as much liquid as possible.

You will notice it is kind of crumbly and squishy, but you can smoosh and shape it.

Now you can put it in your molds at this point but we discovered that if you put the curds in a jar or bowl, soaking in vinegar for an hour, you will get a much smoother final product. Plus they are more white if you do this extra step. If you do the extra vinegar soak, once the hour is up, repeat the straining, and paper towel drying process again. This time you will notice it is smoother in texture and no longer crumbly.

During the vinegar soak you can add some food colouring if you want. Just put a few drops in with the vinegar while it is soaking and it will colour the curds. Or make yours glow in the dark with our favourite trick!

Now squish it into your molds. We used silicone molds to make Lego minifigs and dinosaurs.

You can also shape it by hand. Roll it to create beads, then use a skewer to put a hole through it before setting it aside to dry. Or flatten it and use some cookie cutters.

The drying process takes time, approximately 2 days depending on your natural humidity levels and how much moisture you removed with the paper towels. But you can remove it from the silicone molds after 24 hours and this will help speed up the drying time.

Once dry, clean up the edges a bit if necessary, just like you would with any other casting. You can do this with just your fingers, a piece of sand paper or other tools. It will be hard plastic now, so it might take a little extra work!

You can paint the final products with either acrylic paints or markers. I used acrylic paints and a sharpie for the faces on mine. Spray them with a clear coat to give them a nice shine once you are finished.

VOILA! Who knew it was so easy, and so much fun, to make plastic from milk!

Our oldest Milk Plastic Toys are over 2 years old now and show no signs of degrading. We haven't done any experiments yet to see if they might break down with moisture, or heat, or sun, but that might go on the books for a future study. They are definitely highly durable!

This is a chemistry experiment working with polymers. Polymers are molecules that have formed a regular chain structure. Milk contains molecules of a protein called Casein. During this reaction between warm milk and acid the casein molecules unfold and form long chains called a polymer. The polymer can be molded and shaped which makes it a plastic. In this case it's called casein plastic or milk plastic because of the type of molecules that created the plastic.

More STEM activities

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Make Milk Plastic in the Kitchen Chemistry Project for Kids

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Make plastic from milk? It seems like some sort of lactose intolerant horror story, but it's actually a really cool science process. Create your own toys, beads, jewelry, and more, with ingredients you have right now in your kitchen. It's so easy and super cool! Disclaimer: This article may contain commission or affiliate links.

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I really liked the potato power lesson because it is a creative way for students to learn about energy and power. Students produce a tangible object at the end of the lesson so they can feel proud about what they accomplished. -Grace Rhine

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Quick Look

Grade Level: 4 (3-5)

Time Required: 45 minutes

Expendable Cost/Group: US $2.00

Group Size: 3

Activity Dependency: None

Subject Areas: Physical Science, Science and Technology

NGSS Performance Expectations:

Summary Students use potatoes to light an LED clock (or light bulb) as they learn how a battery works in a simple circuit and how chemical energy changes to electrical energy. As they learn more about electrical energy, they better understand the concepts of voltage, current and resistance.
This engineering curriculum aligns to Next Generation Science Standards (NGSS).

Engineering Connection

Engineers use batteries to store energy in a wide range of situations. A solid electrolyte battery is most suitable in very extreme weather conditions, while nickel-zinc batteries work best in electric vehicles. Energy engineers continually evolve technology to improve the performance and life-cycle costs of batteries that store solar and wind energy. When designing a battery, engineers keep in mind the needs of the application, and use different substances to create current flow. They consider characteristics such as power output, ability to recharge, reliability, size, safety, heat generation, length of life cycle, abuse tolerance, cost and ability to be recycled. Isn't the power of engineering creativity amazing?

Learning Objectives

After this activity, students should be able to:

Describe the flow of electrical energy through a simple circuit.

Explain why a light bulb may take more than one battery to light up.

Explain the role of electrical engineers in the development of electricity sources and the products that use electricity.

Educational Standards

Each TeachEngineering lesson or activity is correlated to one or more K-12 science, technology, engineering or math (STEM) educational standards.

All 100,000+ K-12 STEM standards covered in TeachEngineering are collected, maintained and packaged by the Achievement Standards Network (ASN), a project of D2L (www.achievementstandards.org).

In the ASN, standards are hierarchically structured: first by source; e.g., by state; within source by type; e.g., science or mathematics; within type by subtype, then by grade, etc.

NGSS Performance Expectation

Click to view other curriculum aligned to this Performance Expectation

This activity focuses on the following Three Dimensional Learning aspects of NGSS:

Science & Engineering Practices

Disciplinary Core Ideas

Crosscutting Concepts

Make observations to produce data to serve as the basis for evidence for an explanation of a phenomenon or test a design solution.

Energy can be moved from place to place by moving objects or through sound, light, or electric currents. Energy is present whenever there are moving objects, sound, light, or heat. When objects collide, energy can be transferred from one object to another, thereby changing their motion. In such collisions, some energy is typically also transferred to the surrounding air; as a result, the air gets heated and sound is produced. Light also transfers energy from place to place. Energy can also be transferred from place to place by electric currents, which can then be used locally to produce motion, sound, heat, or light. The currents may have been produced to begin with by transforming the energy of motion into electrical energy.

Energy can be transferred in various ways and between objects.

Suggest an alignment not listed above

Materials List

To make a potato battery, each group needs:

3 copper pennies (or copper strips), one per potato

3 zinc nails; these are galvanized nails, available at hardware stores

5 insulated wires, 15-20 cm (6-8 inches) long, with alligator clips at the ends

1 low-current, light emitting diode (LED) clock (or LCD clock) requiring ~1.5 volts (or a small LED)

OR above materials can be purchased cumulatively in a kit, available online

For the entire class to share or one per team:

(optional) multimeter(s) or voltmeter(s); a multimeter measures current, voltage and resistance of a circuit; available at Radio Shack or other electronics stores or websites

Worksheets and Attachments
Visit [www.teachengineering.org/activities/view/cub_energy2_lesson04_activity2] to print or download.

Introduction/Motivation

What is electrical energy? From where does it come? Can you think of anything that needs electrical energy to work? How about lamps, music players, TVs and ovens? How do we get the power to run these devices? What role do electrical engineers play in improving our lives?

One place we can find electrical energy in our homes is at a wall outlet. So, how does electrical energy reach the wall outlet in our house? The energy comes from an electrical power plant, which usually makes electrical energy from burning fossil fuels, such as coal and oil. The heat energy from the burning fuel heats up water. When the water boils, it becomes steam, which flows through a pipe into a turbine (a wheel with blades). As the turbine spins from the steam, it turns a generator (a spinning magnet) that unbalances the charges in nearby atoms and produces a current of electricity. The electrical current flows through protected wires to our house.

How else can we power electrical appliances? That's right, from a battery. A battery works by providing electrons with a solution in which they can move around. Have you ever noticed that some batteries have a copper end that is positive (shown with a plus [+] sign) and another end that is negative (shown with a minus [-] sign)? Zinc is a metal that likes to give its electrons to copper. Usually, zinc just gives its electrons to copper and then the process stops. However, if you provide the electrons with a solution (called an electrolyte) to help them move to the copper, and you give the electrons a wire in which they can move from the copper back to the zinc, you can produce a circuit and a flowing path of electrical energy. (Note: Conventional current flows from positive to negative, so from the copper, through the wire, back to the zinc. The electrons actually flow negative to positive.)

A circuit is a complete path of electrical energy. This means that electrical energy or charge is produced or stored somewhere ( voltage) and has a path for the charge to flow (or current). Another part of a circuit is a resistance, such as a light bulb. Electrical engineers create circuits to help electrical energy perform work, such as lighting a room or keeping food cold. An appliance, light bulb or almost any device that uses electrical energy is a resistance. A resistance prevents or slows an electrical current or charge from moving. When electrical current flows through a source of resistance, it can be changed into light or heat or sound. Even though you cannot see it, the light bulb or appliance slows down the electrical charge.

Electrical engineers help develop the many modern products and appliances that require electrical energy. Electrical engineers also help create the technology used to generate the electrical energy in power plants in the first place. These engineers know a lot about circuits and they continually work to find better ways to store electrical charge and generate electrical current without using nonrenewable fossil fuels such as coal and oil. These electrical engineers are very important in almost everything we do! Essentially, electrical engineers create improvements for society and help save our planet for future generations. Today, we are going to be electrical engineers and learn more about how electrical energy works in a circuit. We are also going to look at generating electrical current from the energy stored in a potato! Do you think we can light a bulb with a potato? Let's try it!

Procedure

Background

How does a potato battery work? The copper (Cu) atoms attract electrons more than the zinc (Zn) atoms. If you place a strip of copper and a strip of zinc in contact with each other, many electrons pass from the zinc to the copper. As they concentrate on the copper, the electrons repel each other. When the force of repulsion between electrons and the force of attraction of electrons to the copper become equalized, the flow of electrons stops. Unfortunately it is not possible to take advantage of this behavior to produce electricity because the flow of charges stops almost immediately. On the other hand, if you bathe the two strips in a conductive solution, and connect them externally with a wire, the reactions between the electrodes and the solution continually furnish the circuit with charges. In this way, the process that produces the electrical energy continues and becomes useful. In a conductive solution, the charge is carried by ions that move through the solution. In the solid state, the ions are not able to move around freely. However, once they are dissolved in water, they become completely mobile. They can "swim" around in the water and thus can respond to an electric current from a battery. That current supplies electrons that cause positive ions to flow in one direction and negative ions to flow in the opposite direction. The ions carry electrical charge from one electrode to another, completing the electrical circuit.

For a conductive solution, use any electrolyte, whether it is an acid, base or salt solution. An electrolyte is a substance whose aqueous solution contains various ions and thus conducts electricity. Therefore, the more free ions a solution has, the better conductor it will be. Many fruits and vegetables contain juices rich in ions and are therefore good electrical conductors.

Like any battery, a potato battery has a limited life span. The electrodes undergo chemical reactions that block the flow of electricity. The electromotive force diminishes and the battery stops working. Usually, what happens is the production of hydrogen at the copper electrode and the zinc electrode acquires deposits of oxides that act as a barrier between the metal and the electrolyte. This is referred to as the electrodes being polarized. To achieve a longer life and higher voltages and current flows, it is necessary to use electrolytes better suited for the purpose. Commercial batteries, apart from their normal electrolyte, contain chemicals with an affinity for hydrogen, which combine with the hydrogen before it can polarize the electrodes.

Before the Activity

With the Students

1. Divide the class into teams of two or three students each. Hand out the materials.

2. Direct groups to carefully place the zinc nails and copper pennies into the potato. Make sure the two different metals do not touch each other in the potato (see Figure 1).

3. Connect one alligator clip to the end of the penny sticking out of the potato and another alligator clip to the end of the nail sticking out of the potato (see Figure 1).

Figure 1. Placement of the nail, penny and alligator clips.

1. (If you have a multimeter) Tell students that a multimeter is an instrument that measures current, voltage and resistance of a circuit, and is a tool (created by and) often used by engineers. Set the multimeter on a low "DC volts" scale for voltage and "DC milliamps" for current, so students can see the charge that one potato can produce. Expect the potato to produce just less than 1 volt. Encourage students to convert the decimal readout from the multimeter to a fraction (for example, 0.82 volts = 82/100 volts).

2. Have the students figure out how many potatoes they need to light their LED clock (or clock). For example, if their potato produces a voltage of 0.8 volts, then they may need two potatoes to power a 1.5 voltage LED.

3. Have students experiment to figure out how to connect two potatoes together. To connect two potatoes in series (to add more voltage), place a penny and nail into a second potato, and connect the wire from the zinc nail in the first potato to the copper penny in the second. Then, add a third wire to the zinc nail in the second potato. Always remember to connect the copper (positive) end of the potato (battery) to the zinc (negative) end of the next potato (see Figure 2).

Figure 2. Activity setup to create a potato battery to power an LED clock.

1. Expect two potatoes in series to be able to light an LED; however, you might need three. Show students how to connect the LEDs to the potato in the correct manner, that is, the positive end of the LED to the negative end of the potato battery (zinc nail) and the negative end of the LED to the positive end of the potato battery (copper penny).

2. Have students discuss how the potatoes provide the electrolyte (solution) for the chemical battery to work. Ask for suggestions of other foods we could try (for example, lemons, berries, apples).

3. Ask students to complete the worksheet either individually or in pairs. After they finish, have them compare answers with a peer or another pair, giving all students time to finish.

Vocabulary/Definitions

conductor: An object that allows the transfer of electrons.

current: The movement of electrons.

electrical energy: Energy produced through the movement of electrons (voltage X current).

electrolyte: A solution that conducts electricity.

energy: The ability to do work.

insulator: An object that inhibits the transfer of electrons.

resistance: Objects or substances that prevent the passage of a steady electric current.

voltage: The amount of energy produced.

Assessment

Pre-Activity Assessment

Brainstorming: In small groups, have students engage in open discussion. Remind them that no idea or suggestion is "silly." All ideas should be respectfully heard. Take an uncritical position, encourage wild ideas and discourage criticism of ideas. Ask students how many items they can think of that run on batteries. As a class, record their ideas on the board.

Quick Poll: Before the activity begins, ask the class a question and tally their responses on the board. Ask: Can we get electrical energy from a fruit or vegetable?

Activity Embedded Assessment

Worksheet /Pairs Check: Have students work individually or in pairs on the Make a Battery Worksheet. After they finish, have them compare answers with a peer or another pair, giving all students time to finish the worksheet.

Hypothesize: Ask each group what would happen if we added more potatoes in a row to our circuits? (Answer: Adding more potatoes in a row is the same as adding batteries in a row. The voltage of each piece of potato is added up. Thus, the voltage of our circuit would increase. On the other hand, the current of our circuit would not increase. Current is not dependent on how many potatoes but is related to the size of each potato individually.)

Post-Activity Assessment

Problem Solving: Present the class with the following math problems and ask students to calculate how many of each vegetable or fruit are needed to light the bulb.

If a lemon produces 1 Volt of energy, how many lemons would you need to light a 2 Volt light bulb? (Answer: 2)

If a potato produces 0.8 Volts of energy, how many potatoes would you need to light a 1.5 Volt light bulb? (Answer: 2)

If a potato produces 0.8 Volts of energy, how many potatoes would you need to light a 3 Volt digital clock? (Answer: 4)

If you have a lemon that produces 1 Volt of energy and an apple that produces 1 Volt of energy, can you light a 3 Volt clock? (Answer: No, you would need one more lemon or apple.)

Diagramming: Engineers must understand how circuits work in order to develop cool new technologies. Draw a picture of your potato battery. Label the battery (voltage) and the resistance (light bulb). Draw an arrow to show the current flow (from the copper end to the zinc end). List two cool products that an engineer could develop that run off a fruit battery.

Troubleshooting Tips

If the LED clock, light or small light bulbs do not work, check the setup of the potato battery. Perhaps the ends are not all connected from negative to positive, or perhaps there is not enough potato voltage. Check the voltage of the potato using a multimeter or voltmeter. Another possibility is having enough voltage, but not enough current to light the bulb, which is why it is recommended to use only very low-volt LED clocks or bulbs. Also, try using more potatoes (i.e., 5 potato halves) to strengthen conductivity. Try different LED colors (for example, the blue LED may work better than the red).

Lemons and oranges also work well for this activity. They work best if you first roll them on a table top, which breaks down the cells inside so more juice flows through the fruit (current).

Some people have more conduction success using copper strips instead of copper pennies (can also wrap the pennies in copper ribbon).

Soaking the potatoes in Gatorade overnight can make them more conductive.

Activity Extensions

At activity end, before students disassemble their potato batteries, it is fun to have the entire class connect their fruit batteries in series, making "a serious tater circle."

Have students try the activity again using different fruits or vegetables! Many fruits and vegetables work, such as lemons, limes, apples and carrots. Have students compare and contrast the performance of different fruits and vegetables.

Have students complete the activity again using an electrolyte solution, such as salt water or vinegar. Have them compare and contrast the performance of different electrolyte solutions.

To add a math component, have students use the multimeter to compare the flow of electricity for several different fruits as well as to the total amount of fruits used. Ask them to graph the results and hypothesize what is happening.

Activity Scaling

Have more advanced students experiment with parallel and series configurations using different numbers of potatoes.

References

Dictionary.com. Lexico Publishing Group, LLC. Accessed September 28, 2005. (Source of some vocabulary definitions, with some adaptation) http://www.dictionary.com

Phillips, W.D. Chapter 2P: Using a Multimeter. Design Electronics (online textbook) DOCTRONICS Educational Publishing, UK. Accessed September 28, 2005. (Good design, technology and electronics resources.) http://www.doctronics.co.uk/meter.htm

Copyright © 2005 by Regents of the University of Colorado

Contributors Sharon D. Perez-Suarez; Jeff Lyng; Malinda Schaefer Zarske; Denise W. Carlson; Janet Yowell

Supporting Program Integrated Teaching and Learning Program, College of Engineering, University of Colorado Boulder

Acknowledgements

The contents of this digital library curriculum were developed under grants from the Fund for the Improvement of Postsecondary Education (FIPSE), U.S. Department of Education, and the National Science Foundation (GK-12 grant no. 0338326). However, these contents do not necessarily represent the policies of the Department of Education or National Science Foundation, and you should not assume endorsement by the federal government.

Last modified: July 9, 2020

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Students use potatoes to light an LED clock (or light bulb) as they learn how a battery works in a simple circuit and how chemical energy changes to electrical energy. As they learn more about electrical energy, they better understand the concepts of voltage, current and resistance.

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I chose the marshmallow catapult because kids love marshmallows. Not only that but it involves them being catapulted across the room. Students would love that and ben entertained while learning about math and science.

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Posted on by ASEE

(Lesson Courtesy COSI Columbus - The Center for Science and Industry). Level: Grades 4 - 8. Time required: 30 to 50 minutes. Click HERE for PDF of activity. Click HERE for version developed by Ohio State University engineering graduate students and Maize Elementary teachers

Overview

This simple catapult activity for students in grades 4 - 8 teaches them how energy is transferred when a plastic spoon is pulled back, then released, rocketing its payload - a single marshmallow.

Background

What's going on? The plastic spoon has an inherent elasticity, which means it will return to its original shape after being deformed. Rubber bands and other elastic objects also have this property. When the spoon is deformed, the force used to cause that deformation is "stored" in the spoon as elastic potential energy. When the spoon is released, the elastic potential energy changes to kinetic energy as the spoon returns to its original shape, carrying the marshmallow along with it. The marshmallow continues to move after the spoon has stopped due to its inertia.

Catapult Information

(from the Museum of Ancient Inventions, Smith College)

The catapult was an ancient siege machine that could hurl heavy objects or shoot arrows with great force and for considerable distances. Some catapults could throw stones weighing as much as 350 pounds for distances greater than 300 feet.

The Greek Dionysius the Elder of Syracuse, who was looking to develop a new type of weapon, invented the catapult about 400 BCE. Thereafter, it became a key weapon in warfare and remained so up through mediaeval times. Two major catapults evolved from Dionysius's invention: the double-armed machine, or ballista, used for shooting arrows, and the single-armed catapult designed for hurling large objects. Although the Romans added wheels to both types of catapult for maneuverability, very little in the design of the machine changed.The reconstruction shown here is of a single-armed stone-hurling catapult, approximately two feet long and one-and-a-half feet tall. Its hurling arm is driven by a cocked, winch-pulled cord.

Standards (Ohio)

Physical Science: 1.6, 3.3, 3.4, 7.2, 7.4

Vocabulary

elasticity, potential energy, kinetic energy, deflection angle

Materials

Plastic spoon

1-2 bags of miniature marshmallows

marking pens

tape measure or meter stick

masking tape

protractor

safety goggles

Procedure
Instruction for teachers:
Set up the classroom so that you have at least 20 feet of open space in front of the launching area for a landing area. Have students put on goggles, then align teams of 3-4 students along one side of a set of long tables or a counter so the catapults will be aimed across the room.

Distribute to each group safety goggles, spoons, marshmallows, protractors, and lengths of masking tape.
Instructions for students:
1. Prepare your catapult by taping a spoon firmly against the edge of a table, perpendicular to the tabletop with the bowl of the spoon facing toward the table.

2. Mark your marshmallows for identification with a pen, using your group initials.

3. Test the setup of your catapult and marshmallow: Hold the marshmallow in the bowl of the spoon. Use your thumb to help anchor the spoon handle against the table.

4. Practice launch: Keeping the end of the spoon handle against the table, launching the marshmallow across the room. (Don't point it at anyone!)

5. Experiment with pulling the spoon back farther to change the angle - what are the results?

Now, determine the best deflection angle - how far you pull back the spoon - to launch the marshmallow the farthest possible distance. Decide how much to deflect the spoon, using a protractor to measure the angle between the spoon and the table. Record the measurements of your deflection angle on a sheet of paper, then launch your marshmallow and measure the distance it travels. Repeat this two more times and compute the average of the three.

6. Now, change the deflection angle of the catapult and repeat. Record the average distance for three separate different catapult angles. Record your results. What angle between the spoon and table launches the marshmallow the farthest?

7. Based on your data, predict the optimum deflection angle.

8. Hold a class contest to find out who can make a marshmallow fly the farthest.

Extensions

Ask the class what would happen if they changed the weight/size of the marshmallow - and how could they do that? Which other techniques could makes the marshmallow go farther? Higher?

Spoons may be made of several different types of plastic. Bring in other plastic spoons and try this experiment. Compare and contrast the results. Look up the properties of the different types of plastic and relate these properties to the results.

For homework, challenge students to come up with their own catapult design - still using the marshmallow load - then allow them to construct, test, and demonstrate their models in class the next day. What innovative solutions did each group devise? Have students evaluate their results and those of their classmates.

Assign students to research the history of catapults. When were they used, and for what purposes?

Resources

More ancient inventions at Smith College's online Museum of Ancient Inventions
http://www.middle-ages.org.uk/catapults.htm http://www.medieval-castle-siege-weapons.com/medieval-catapults.html
Filed under: Class Activities, Grades 6-8, Grades K-5, Grades K-5, Lesson Plans

Tags: catapult, Class Activities, forces and motion, Fun & Games, Grades 4 - 8, Grades K-5, Newton's Laws, Physical Science, Physics, trebuchet

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eGFI - For Teachers " Activity: Catapult Marshmallow Launch

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Posted on by ASEE (Lesson Courtesy COSI Columbus - The Center for Science and Industry). Level: Grades 4 - 8. Time required: 30 to 50 minutes. Click HERE for PDF of activity.

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This was one of the coolest lessons out of everything I saw. I remember doing something like this is school and it blew my mind to see. I think all kids are shocked by seeing this work with a potato of all things. It is definitely geared more towards older students.

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Quick Look

Grade Level: 4 (3-5)

Time Required: 45 minutes

Expendable Cost/Group: US $2.00

Group Size: 3

Activity Dependency: None

Subject Areas: Physical Science, Science and Technology

NGSS Performance Expectations:

Summary Students use potatoes to light an LED clock (or light bulb) as they learn how a battery works in a simple circuit and how chemical energy changes to electrical energy. As they learn more about electrical energy, they better understand the concepts of voltage, current and resistance.
This engineering curriculum aligns to Next Generation Science Standards (NGSS).

Engineering Connection

Engineers use batteries to store energy in a wide range of situations. A solid electrolyte battery is most suitable in very extreme weather conditions, while nickel-zinc batteries work best in electric vehicles. Energy engineers continually evolve technology to improve the performance and life-cycle costs of batteries that store solar and wind energy. When designing a battery, engineers keep in mind the needs of the application, and use different substances to create current flow. They consider characteristics such as power output, ability to recharge, reliability, size, safety, heat generation, length of life cycle, abuse tolerance, cost and ability to be recycled. Isn't the power of engineering creativity amazing?

Learning Objectives

After this activity, students should be able to:

Describe the flow of electrical energy through a simple circuit.

Explain why a light bulb may take more than one battery to light up.

Explain the role of electrical engineers in the development of electricity sources and the products that use electricity.

Educational Standards

Each TeachEngineering lesson or activity is correlated to one or more K-12 science, technology, engineering or math (STEM) educational standards.

All 100,000+ K-12 STEM standards covered in TeachEngineering are collected, maintained and packaged by the Achievement Standards Network (ASN), a project of D2L (www.achievementstandards.org).

In the ASN, standards are hierarchically structured: first by source; e.g., by state; within source by type; e.g., science or mathematics; within type by subtype, then by grade, etc.

NGSS Performance Expectation

Click to view other curriculum aligned to this Performance Expectation

This activity focuses on the following Three Dimensional Learning aspects of NGSS:

Science & Engineering Practices

Disciplinary Core Ideas

Crosscutting Concepts

Make observations to produce data to serve as the basis for evidence for an explanation of a phenomenon or test a design solution.

Energy can be moved from place to place by moving objects or through sound, light, or electric currents. Energy is present whenever there are moving objects, sound, light, or heat. When objects collide, energy can be transferred from one object to another, thereby changing their motion. In such collisions, some energy is typically also transferred to the surrounding air; as a result, the air gets heated and sound is produced. Light also transfers energy from place to place. Energy can also be transferred from place to place by electric currents, which can then be used locally to produce motion, sound, heat, or light. The currents may have been produced to begin with by transforming the energy of motion into electrical energy.

Energy can be transferred in various ways and between objects.

Suggest an alignment not listed above

Materials List

To make a potato battery, each group needs:

3 copper pennies (or copper strips), one per potato

3 zinc nails; these are galvanized nails, available at hardware stores

5 insulated wires, 15-20 cm (6-8 inches) long, with alligator clips at the ends

1 low-current, light emitting diode (LED) clock (or LCD clock) requiring ~1.5 volts (or a small LED)

OR above materials can be purchased cumulatively in a kit, available online

For the entire class to share or one per team:

(optional) multimeter(s) or voltmeter(s); a multimeter measures current, voltage and resistance of a circuit; available at Radio Shack or other electronics stores or websites

Worksheets and Attachments
Visit [www.teachengineering.org/activities/view/cub_energy2_lesson04_activity2] to print or download.

Introduction/Motivation

What is electrical energy? From where does it come? Can you think of anything that needs electrical energy to work? How about lamps, music players, TVs and ovens? How do we get the power to run these devices? What role do electrical engineers play in improving our lives?

One place we can find electrical energy in our homes is at a wall outlet. So, how does electrical energy reach the wall outlet in our house? The energy comes from an electrical power plant, which usually makes electrical energy from burning fossil fuels, such as coal and oil. The heat energy from the burning fuel heats up water. When the water boils, it becomes steam, which flows through a pipe into a turbine (a wheel with blades). As the turbine spins from the steam, it turns a generator (a spinning magnet) that unbalances the charges in nearby atoms and produces a current of electricity. The electrical current flows through protected wires to our house.

How else can we power electrical appliances? That's right, from a battery. A battery works by providing electrons with a solution in which they can move around. Have you ever noticed that some batteries have a copper end that is positive (shown with a plus [+] sign) and another end that is negative (shown with a minus [-] sign)? Zinc is a metal that likes to give its electrons to copper. Usually, zinc just gives its electrons to copper and then the process stops. However, if you provide the electrons with a solution (called an electrolyte) to help them move to the copper, and you give the electrons a wire in which they can move from the copper back to the zinc, you can produce a circuit and a flowing path of electrical energy. (Note: Conventional current flows from positive to negative, so from the copper, through the wire, back to the zinc. The electrons actually flow negative to positive.)

A circuit is a complete path of electrical energy. This means that electrical energy or charge is produced or stored somewhere ( voltage) and has a path for the charge to flow (or current). Another part of a circuit is a resistance, such as a light bulb. Electrical engineers create circuits to help electrical energy perform work, such as lighting a room or keeping food cold. An appliance, light bulb or almost any device that uses electrical energy is a resistance. A resistance prevents or slows an electrical current or charge from moving. When electrical current flows through a source of resistance, it can be changed into light or heat or sound. Even though you cannot see it, the light bulb or appliance slows down the electrical charge.

Electrical engineers help develop the many modern products and appliances that require electrical energy. Electrical engineers also help create the technology used to generate the electrical energy in power plants in the first place. These engineers know a lot about circuits and they continually work to find better ways to store electrical charge and generate electrical current without using nonrenewable fossil fuels such as coal and oil. These electrical engineers are very important in almost everything we do! Essentially, electrical engineers create improvements for society and help save our planet for future generations. Today, we are going to be electrical engineers and learn more about how electrical energy works in a circuit. We are also going to look at generating electrical current from the energy stored in a potato! Do you think we can light a bulb with a potato? Let's try it!

Procedure

Background

How does a potato battery work? The copper (Cu) atoms attract electrons more than the zinc (Zn) atoms. If you place a strip of copper and a strip of zinc in contact with each other, many electrons pass from the zinc to the copper. As they concentrate on the copper, the electrons repel each other. When the force of repulsion between electrons and the force of attraction of electrons to the copper become equalized, the flow of electrons stops. Unfortunately it is not possible to take advantage of this behavior to produce electricity because the flow of charges stops almost immediately. On the other hand, if you bathe the two strips in a conductive solution, and connect them externally with a wire, the reactions between the electrodes and the solution continually furnish the circuit with charges. In this way, the process that produces the electrical energy continues and becomes useful. In a conductive solution, the charge is carried by ions that move through the solution. In the solid state, the ions are not able to move around freely. However, once they are dissolved in water, they become completely mobile. They can "swim" around in the water and thus can respond to an electric current from a battery. That current supplies electrons that cause positive ions to flow in one direction and negative ions to flow in the opposite direction. The ions carry electrical charge from one electrode to another, completing the electrical circuit.

For a conductive solution, use any electrolyte, whether it is an acid, base or salt solution. An electrolyte is a substance whose aqueous solution contains various ions and thus conducts electricity. Therefore, the more free ions a solution has, the better conductor it will be. Many fruits and vegetables contain juices rich in ions and are therefore good electrical conductors.

Like any battery, a potato battery has a limited life span. The electrodes undergo chemical reactions that block the flow of electricity. The electromotive force diminishes and the battery stops working. Usually, what happens is the production of hydrogen at the copper electrode and the zinc electrode acquires deposits of oxides that act as a barrier between the metal and the electrolyte. This is referred to as the electrodes being polarized. To achieve a longer life and higher voltages and current flows, it is necessary to use electrolytes better suited for the purpose. Commercial batteries, apart from their normal electrolyte, contain chemicals with an affinity for hydrogen, which combine with the hydrogen before it can polarize the electrodes.

Before the Activity

With the Students

1. Divide the class into teams of two or three students each. Hand out the materials.

2. Direct groups to carefully place the zinc nails and copper pennies into the potato. Make sure the two different metals do not touch each other in the potato (see Figure 1).

3. Connect one alligator clip to the end of the penny sticking out of the potato and another alligator clip to the end of the nail sticking out of the potato (see Figure 1).

Figure 1. Placement of the nail, penny and alligator clips.

1. (If you have a multimeter) Tell students that a multimeter is an instrument that measures current, voltage and resistance of a circuit, and is a tool (created by and) often used by engineers. Set the multimeter on a low "DC volts" scale for voltage and "DC milliamps" for current, so students can see the charge that one potato can produce. Expect the potato to produce just less than 1 volt. Encourage students to convert the decimal readout from the multimeter to a fraction (for example, 0.82 volts = 82/100 volts).

2. Have the students figure out how many potatoes they need to light their LED clock (or clock). For example, if their potato produces a voltage of 0.8 volts, then they may need two potatoes to power a 1.5 voltage LED.

3. Have students experiment to figure out how to connect two potatoes together. To connect two potatoes in series (to add more voltage), place a penny and nail into a second potato, and connect the wire from the zinc nail in the first potato to the copper penny in the second. Then, add a third wire to the zinc nail in the second potato. Always remember to connect the copper (positive) end of the potato (battery) to the zinc (negative) end of the next potato (see Figure 2).

Figure 2. Activity setup to create a potato battery to power an LED clock.

1. Expect two potatoes in series to be able to light an LED; however, you might need three. Show students how to connect the LEDs to the potato in the correct manner, that is, the positive end of the LED to the negative end of the potato battery (zinc nail) and the negative end of the LED to the positive end of the potato battery (copper penny).

2. Have students discuss how the potatoes provide the electrolyte (solution) for the chemical battery to work. Ask for suggestions of other foods we could try (for example, lemons, berries, apples).

3. Ask students to complete the worksheet either individually or in pairs. After they finish, have them compare answers with a peer or another pair, giving all students time to finish.

Vocabulary/Definitions

conductor: An object that allows the transfer of electrons.

current: The movement of electrons.

electrical energy: Energy produced through the movement of electrons (voltage X current).

electrolyte: A solution that conducts electricity.

energy: The ability to do work.

insulator: An object that inhibits the transfer of electrons.

resistance: Objects or substances that prevent the passage of a steady electric current.

voltage: The amount of energy produced.

Assessment

Pre-Activity Assessment

Brainstorming: In small groups, have students engage in open discussion. Remind them that no idea or suggestion is "silly." All ideas should be respectfully heard. Take an uncritical position, encourage wild ideas and discourage criticism of ideas. Ask students how many items they can think of that run on batteries. As a class, record their ideas on the board.

Quick Poll: Before the activity begins, ask the class a question and tally their responses on the board. Ask: Can we get electrical energy from a fruit or vegetable?

Activity Embedded Assessment

Worksheet /Pairs Check: Have students work individually or in pairs on the Make a Battery Worksheet. After they finish, have them compare answers with a peer or another pair, giving all students time to finish the worksheet.

Hypothesize: Ask each group what would happen if we added more potatoes in a row to our circuits? (Answer: Adding more potatoes in a row is the same as adding batteries in a row. The voltage of each piece of potato is added up. Thus, the voltage of our circuit would increase. On the other hand, the current of our circuit would not increase. Current is not dependent on how many potatoes but is related to the size of each potato individually.)

Post-Activity Assessment

Problem Solving: Present the class with the following math problems and ask students to calculate how many of each vegetable or fruit are needed to light the bulb.

If a lemon produces 1 Volt of energy, how many lemons would you need to light a 2 Volt light bulb? (Answer: 2)

If a potato produces 0.8 Volts of energy, how many potatoes would you need to light a 1.5 Volt light bulb? (Answer: 2)

If a potato produces 0.8 Volts of energy, how many potatoes would you need to light a 3 Volt digital clock? (Answer: 4)

If you have a lemon that produces 1 Volt of energy and an apple that produces 1 Volt of energy, can you light a 3 Volt clock? (Answer: No, you would need one more lemon or apple.)

Diagramming: Engineers must understand how circuits work in order to develop cool new technologies. Draw a picture of your potato battery. Label the battery (voltage) and the resistance (light bulb). Draw an arrow to show the current flow (from the copper end to the zinc end). List two cool products that an engineer could develop that run off a fruit battery.

Troubleshooting Tips

If the LED clock, light or small light bulbs do not work, check the setup of the potato battery. Perhaps the ends are not all connected from negative to positive, or perhaps there is not enough potato voltage. Check the voltage of the potato using a multimeter or voltmeter. Another possibility is having enough voltage, but not enough current to light the bulb, which is why it is recommended to use only very low-volt LED clocks or bulbs. Also, try using more potatoes (i.e., 5 potato halves) to strengthen conductivity. Try different LED colors (for example, the blue LED may work better than the red).

Lemons and oranges also work well for this activity. They work best if you first roll them on a table top, which breaks down the cells inside so more juice flows through the fruit (current).

Some people have more conduction success using copper strips instead of copper pennies (can also wrap the pennies in copper ribbon).

Soaking the potatoes in Gatorade overnight can make them more conductive.

Activity Extensions

At activity end, before students disassemble their potato batteries, it is fun to have the entire class connect their fruit batteries in series, making "a serious tater circle."

Have students try the activity again using different fruits or vegetables! Many fruits and vegetables work, such as lemons, limes, apples and carrots. Have students compare and contrast the performance of different fruits and vegetables.

Have students complete the activity again using an electrolyte solution, such as salt water or vinegar. Have them compare and contrast the performance of different electrolyte solutions.

To add a math component, have students use the multimeter to compare the flow of electricity for several different fruits as well as to the total amount of fruits used. Ask them to graph the results and hypothesize what is happening.

Activity Scaling

Have more advanced students experiment with parallel and series configurations using different numbers of potatoes.

References

Dictionary.com. Lexico Publishing Group, LLC. Accessed September 28, 2005. (Source of some vocabulary definitions, with some adaptation) http://www.dictionary.com

Phillips, W.D. Chapter 2P: Using a Multimeter. Design Electronics (online textbook) DOCTRONICS Educational Publishing, UK. Accessed September 28, 2005. (Good design, technology and electronics resources.) http://www.doctronics.co.uk/meter.htm

Copyright © 2005 by Regents of the University of Colorado

Contributors Sharon D. Perez-Suarez; Jeff Lyng; Malinda Schaefer Zarske; Denise W. Carlson; Janet Yowell

Supporting Program Integrated Teaching and Learning Program, College of Engineering, University of Colorado Boulder

Acknowledgements

The contents of this digital library curriculum were developed under grants from the Fund for the Improvement of Postsecondary Education (FIPSE), U.S. Department of Education, and the National Science Foundation (GK-12 grant no. 0338326). However, these contents do not necessarily represent the policies of the Department of Education or National Science Foundation, and you should not assume endorsement by the federal government.

Last modified: July 9, 2020

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Students use potatoes to light an LED clock (or light bulb) as they learn how a battery works in a simple circuit and how chemical energy changes to electrical energy. As they learn more about electrical energy, they better understand the concepts of voltage, current and resistance.