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Hot gases expand, cold gases contract!

All gases have freely moving molecules. As you add more heat to a gas, the molecules move faster and push harder against the sides of a vessel that holds them. The more the gas molecules collide against the sides of the vessel, the greater the air pressure.

By covering the glass bottle in hot water, the heat energy moved into the contained air which then increased the air molecules movement inside the bottle and therefore the air pressure as well. This increased air pressure expanded the balloon!

Variable testing
More about variable testing here

Try different size balloons. Can you inflate each one?

With an adult, try different water temperatures

Try different shaped bottles

Going further

What you have observed is an example of how the pressure of a gas is proportional to the temperature of the gas. In simple terms, this means that if you increase the pressure, you increase the temperature. This works both ways, if you increase the temperature, you increase the pressure!

This is Gay Lussac's Law, stated more precisely as below:
The pressure of a given mass of gas varies directly with the absolute temperature of the gas, when the volume is kept constan
which can be written mathematically as follows:

whereby:

P1 = Initial pressure

T1 = Initial temperature

P2 = Final pressure

T1 = Final temperature

You can explore the effect of changing temperature, volume & pressure in the interactive simulation by the University of Colarado Boulder PhET Interactive Simulations project

Just click on "Ideal" which refers to what happens to an Ideal Gas, which is a pretend gas which has molecules that don't chemically react with each other. This means that you can see what happens to these molecules as you change the temperature, pressure and volume of the container much more easily.

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Hot air expands demonstration for schools : Fizzics Education

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Hot gases expand, cold gases contract! All gases have freely moving molecules. As you add more heat to a gas, the molecules move faster and push harder against the sides of a vessel that holds them. The more the gas molecules collide against the sides of the vessel, the greater the air pressure.

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Follow FizzicsEd 150 Science Experiments:

You will need:

1 clear glass jar

1 match

A kettle with water

A rubber glove

Adult supervision needed
Copyright

1

With adult help, boil your kettle and allow the water to sit until it cools a little. You don't need really hot water, just enough for it to be still steaming.

Once the kettle has cooled a bit, carefully pour a small amount of water into the glass jar (just enough to cover the bottom of the jar).

2

With adult help, light a match and allow it to burn for a couple of seconds. Now blow the match out and drop it into the glass jar to put out the smouldering match in the water.

3

Quickly stretch your rubber glove over the entrance of the glass jar. The rubber glove should be stretched tightly across the jar but still loose enough to be able to move up and down without tearing.

Using a latex glove:
We've found that it is easier to then clamp your hands around the side of the jar so that the rubber glove fingers are not involved in the experiment.

Using a laundry rubber glove:
If you are using a laundry glove (and you have a large enough jar), another way is to place the glove fingers all the way into the jar and then roll the opening of the glove over the entrance of the jar. The glove should then be entirely inside the jar and be upside down when you place the jar on the table.

4

Now it's time to make your cloud in a jar!

Using a latex glove
Pinch the middle of the stretched rubber and pull upwards.

Using a laundry rubber glove:
Place your hand as far into the upside-down glove as you can. Now pull the glove upwards.

In both versions, you should see a cloud momentarily form in the jar. You can then repeat the demonstration by pushing the glove back inside the jar and then pulling the glove out again.

5

Troubleshooting

If you find there is too much condensation inside your jar to see the cloud, your water is too hot.

If the cloud doesn't form when you pull on the glove, either not enough water vapour is in the air inside the jar or you don't have enough smoke inside the jar or finally the glove is not being out far enough to change the volume enough for the cloud to form.

7

Online courses for teachers & parents

- Help students learn how science really works

What is going on?

Adding hot water into the jar allows water vapour to fill the jar. This increases the humidity within the jar, however it is too warm for the water vapour molecules to condense and form a cloud. Temperature is a measure of how quickly molecules are moving and colliding. When the air molecules inside the jar are closer together the temperature can remain higher than when you separate these air molecules. By pulling on the rubber glove you were able to lower the temperature by increasing the volume of the air space (which means less collisions between the air molecules). The cloud formed inside the jar when the temperature was low enough for water molecules to condense around the smoke particles in the air.

Variables to test
More on variables here

Try different temperatures of water in the jar. What is the minimum temperature needed for the cloud to form?

Try using hairspray instead of smoke form a match. Does this make this easier or harder to form a cloud?

Try large vs small jars.

Years 3 to 6

Maximum 30 students

School science show (NSW & VIC)

60 minutes

Online Class Available

Hands-on Kids Science Party

>20 hands on science experiments

Gigantic bubbles

Slime making

Professional science show

STEM Full Day Accelerator - Primary

Designed from real classroom experiences, this modular day helps you create consistently effective science learning that directly address the new curriculum with easily accessible and cost-effective materials.

Years 1 to 6

Maximum 30 students

School workshop (NSW & VIC)

60 or 90 minutes

Online Class Available

With adult help, boil your kettle and allow the water to sit until it cools a little. You don't need really hot water, just enough for it to be still steaming.

Once the kettle has cooled a bit, carefully pour a small amount of water into the glass jar (just enough to cover the bottom of the jar).

With adult help, light a match and allow it to burn for a couple of seconds. Now blow the match out and drop it into the glass jar to put out the smouldering match in the water.

Quickly stretch your rubber glove over the entrance of the glass jar. The rubber glove should be stretched tightly across the jar but still loose enough to be able to move up and down without tearing.

Using a latex glove:
We've found that it is easier to then clamp your hands around the side of the jar so that the rubber glove fingers are not involved in the experiment.

Using a laundry rubber glove:
If you are using a laundry glove (and you have a large enough jar), another way is to place the glove fingers all the way into the jar and then roll the opening of the glove over the entrance of the jar. The glove should then be entirely inside the jar and be upside down when you place the jar on the table.

Now it's time to make your cloud in a jar!

Using a latex glove
Pinch the middle of the stretched rubber and pull upwards.

Using a laundry rubber glove:
Place your hand as far into the upside-down glove as you can. Now pull the glove upwards.

In both versions, you should see a cloud momentarily form in the jar. You can then repeat the demonstration by pushing the glove back inside the jar and then pulling the glove out again.

Troubleshooting

If you find there is too much condensation inside your jar to see the cloud, your water is too hot.

If the cloud doesn't form when you pull on the glove, either not enough water vapour is in the air inside the jar or you don't have enough smoke inside the jar or finally the glove is not being out far enough to change the volume enough for the cloud to form.

School science visits since 2004!

- Curriculum-linked & award-winning incursions.

- Over 40 primary & high school programs to choose from.

- Designed by experienced educators.

- Over 2 million students reached.

- Face to face incursions & online programs available.

- Early learning centre visits too!

Online courses for teachers & parents

- Help students learn how science really works

Years 3 to 6

Maximum 30 students

School science show (NSW & VIC)

60 minutes

Online Class Available

Years 3 to 6

Maximum 30 students

School science show (NSW & VIC)

60 minutes

Online Class Available

Hands-on Kids Science Party

>20 hands on science experiments

Gigantic bubbles

Slime making

Professional science show

>20 hands on science experiments

Gigantic bubbles

Slime making

Professional science show

STEM Full Day Accelerator - Primary

Designed from real classroom experiences, this modular day helps you create consistently effective science learning that directly address the new curriculum with easily accessible and cost-effective materials.

Designed from real classroom experiences, this modular day helps you create consistently effective science learning that directly address the new curriculum with easily accessible and cost-effective materials.

Years 1 to 6

Maximum 30 students

School workshop (NSW & VIC)

60 or 90 minutes

Online Class Available

Years 1 to 6

Maximum 30 students

School workshop (NSW & VIC)

60 or 90 minutes

Online Class Available

The kids LOVED it!!! Thank you so much!!!
-C. Lancaster - Ellwood Elementary

Thank you so much for joining us in my science classes this morning. My students had a lot of fun learning more about sound. They loved that you are from Australia - they couldn't believe how early in the morning it was on Friday and that you were zooming with us.
-L. Corcoran - North Ridgeville City Schools OH

I wanted to say thanks for a fantastic day of Zoom presentations. Rusty was a phenomenal presenter - highly engaging and knowledgeable, but also very professional. Although we weren't able to have him in person, he still did a wonderful job. The boys loved it!

-J.Graham - The Scots College

On behalf of Salamah College staff and students, we would like to say a big thank you for your kind effort and hard work. The experiments you put together were astonishing and engaging. Your energetic approach grasped the students' attention and kept them engaged throughout the show. We highly appreciate you reaching out to our school. It was great meeting you. Thank you, Salamah College Team,
-S. Elkordy - Salamah College

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Make a cloud in a jar : Fizzics Education

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Follow FizzicsEd 150 Science Experiments: 1 clear glass jar 1 match A kettle with water A rubber glove Adult supervision needed Copyright 1 With adult help, boil your kettle and allow the water to sit until it cools a little. You don't need really hot water, just enough for it to be still steaming.

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Hmmmm, you've completed an experiment whose results are quite tricky to explain.
Did you find that the hot water froze first? Under some conditions this can happen...

We started with two containers of water, which were identical in shape and held identical amounts of water. The only difference between the two was that the water in one was at a higher (uniform) temperature than the water in the other. Of course, if the hot water had started at 99.9° C, and the cold water at 0.01° C, then clearly under those circumstances, the initially cooler water would have frozen first. However, under some conditions the initially warmer water will freeze first - if that happens, you have seen the Mpemba effect which describes the phenomenon.

How does it work you might ask? Several ideas have been put forward and no-one really is sure as to which effect plays the biggest role:

1. As the initially warmer water cools to the freezer temperature, it may lose significant amounts of water to evaporation. The reduced mass will make it easier for the warmer water to cool and freeze than the colder water.

2. A convection current may have been setup in the warmer water. As the warmer water cooled it lost heat primarily through the surface of the liquid faster than the colder water. This is due to a great temperature difference between the cold freezer air and the warm water. The water from the bottom of the cup then rose to the water surface, bringing more heat energy to the cold freezer air. As the current is greater in the warmer water than the cold water, a greater amount of liquid got exposed to the cold freezer air. Think of a fan forced oven, circulating the hot air through the oven heats the oven faster than just allowing the air to sit still... bakers have known this over a thousand of years!

More on temperature and water rising or falling
3. The surrounding air around the cups may have more movement around the warmer cup, therefore drawing heat energy away from the warmer cup more effectively.

4. Warm water holds less dissolved gas than cold water. There have been some suggestions that the presence of dissolved gases impede the production of convection currents in the colder water.

5. The cold water may have supercooled, therefore not forming a solid as quick as the hot water.

Quote: "I often put boiling water in the freezer. Then whenever I need boiling water, I simply defrost it." -Gracie Allen.

Variables to test
More on variables here

What happens if you add salt to the water?

Does it make a difference if you change the volume of water?

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Does hot water freeze faster than cold water? | Fizzics Education

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Hmmmm, you've completed an experiment whose results are quite tricky to explain. Did you find that the hot water froze first? Under some conditions this can happen... We started with two containers of water, which were identical in shape and held identical amounts of water.

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Farm Animals Names and Sounds for Kids to Learn | Learning Farm Animal Names and Sounds for Children

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Making a marshmallow and spaghetti tower..

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Making a marshmallow and spaghetti tower..

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Build a Spaghetti Tower Challenge | Holmes + Holmes

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Refraction of Light - Why does a pencil look bent in water? | #aumsum #kids #science

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Easy light and sound science experiments you can do at home! Click on the experiment image or the view experiment link below for each experiment on this page to see the materials needed and procedure. Have fun trying these experiments at home or use them for SCIENCE FAIR PROJECT IDEAS.

Make Music With This Easy Sound Experiment

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Easy light and sound science experiments you can do at home! Click on the experiment image or the view experiment link below for each experiment on this page to see the materials needed and procedure. Have fun trying these experiments at home or use them for SCIENCE FAIR PROJECT IDEAS.

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A fun science experiment and music lesson all in one! This easy experiment allows kids to learn and make noise (music) in the process.

Kids can explore and investigate sound waves, pitch, and more as they create their own simple musical instrument. Watch our demonstration video below then print out our materials list and instruction sheet to get started. An easy to understand explanation of how the experiment works is included.

JUMP TO SECTION: Instructions | Video Tutorial | How it Works

Supplies Needed

Set of Glasses of equal shape and size

Water

Metal Spoon

Food Coloring (optional)

Musical Jar Science Experiment Instructions

Step 1 - Begin with empty glass jars of the same shape and size. Use the metal spoon to tap on each one. What do you observe? Do they sound the same? Yes! At this point you'll notice that each sound is the same. Now let's find out if we can make the sounds different.

Step 2 - Pour water into each jar. Make sure that the water level is different in each jar.

Step 3 - Add food coloring to each jar to make it easier to see the different water levels. You can use the same color in each jar or use a rainbow of colors as we did. This is an optional step, but it adds to the fun!

Step 4 - Use the same metal spoon to tap on the jars again. Listen carefully so you can hear how the sounds have changed. Do you know the reason why the jars make different sounds? Find out the answer in the how does this experiment work section below.

Video Tutorial

Musical Jars Science Experiment Step by Step Instructions Video

How Does the Science Experiment Work

Sound is a disturbance that travels through a medium as a wave. In this experiment, tapping on the jars with the spoon disturbs the particles of the jar causing them to vibrate. The vibrations in the jar are transferred to the air surrounding the jar, creating a sound wave. When the jars are all empty, the vibrations and the sounds are all the same. Adding different amounts of water to the jars causes the vibrations (and sound) to change.

You can change the pitch of the sound produced by the amount of water you put in the glass. Pitch is how high or low sound seems to a person and it depends on the frequency of the sound wave. When you add more water to the glass, the pitch is low. This is because the high volume of water in the glass makes it more difficult for the glass particles to vibrate, so the vibrations of the glass are slower and they have a lower frequency. When you add less water to the glass, the pitch is high. This is because the low volume of water in the glass allows the glass particle to vibrate more easily, so the vibrations of the glass are faster and have a higher frequency.

More Science Fun

After your kids understand the concepts of the experiment, turn it into a music lesson. Take turns playing songs and guessing the melody.

For another fun sound experiment, enjoy banging on a pan with this How to See Sound Experiment!

I hope you enjoyed the experiment. Here are some printable instructions:

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A fun science experiment and music lesson all in one! This easy experiment allows kids to learn and make noise (music) in the process. Kids can explore and investigate sound waves, pitch, and more as they create their own simple musical instrument. Watch our demonstration video below then print out our materials list and instruction [...]

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Magic trick? No, but the results of this experiment are pretty surprising. Kids (and adults) will stare in amazement and scratch their heads wondering what causes the arrow in this experiment to change direction right before their eyes! The secret is light refraction.

Exploring light refraction couldn't be easier or more fun, simply preview the experiment with our demonstration video below and find an easy to understand explanation of how it works below.

JUMP TO SECTION: Instructions | Video Tutorial | How it Works

Supplies Needed

Light Refraction Science Experiment Instructions

Step 1 - Get a sheet of paper and draw two arrows on it. One arrow near the top and one arrow near the bottom. Make the arrows point in the same direction.

Step 2 - Fill a glass with water.

Step 3 - Slowly lower the piece of paper behind the glass of water.

Step 4 - Look through the glass of water and watch what happens. Do you know why the arrow appears to change directions? Find out the answer in the how does this experiment work section below.

Video Tutorial

Light Refraction Science Experiment Step by Step Instructional Video
How Does the Science Experiment Work

The scientific concept that is at work in this experiment is called refraction. Refraction is the bending of light. Refraction occurs when light travels from one medium to another (ie. air to water, water to air).

During the experiment, the light traveled from the image through the air, then through the glass cup into the water, and finally out of the glass cup and into the air once more before it reached our eyes. Light refracts as it passes from one medium to the next because it travels at different speeds through those mediums. Light travels fastest through air, a little slower through water, and even slower through glass.

This means that the light bends once when it travels through the glass cup into the water, and then it bends again when it travels out of the glass cup and into the air. As a result, the light paths cross and the image appears to be flipped horizontally (left/right).

Light Refraction Examples

The following are examples of refraction that occur all around us.

Glasses or Contacts - The lenses of glasses and contacts are designed to bend light in ways that help a persons improve vision.

Rainbow - Rainbows are formed when the rays of sunlight bend (refract) when they travel through rain drops.

Cameras - A camera works because the lens causes the light rays to refract.

More Experiments that Show Light Refraction

Refraction of Light Science Experiment - Watch as the straw appears to bend in this experiment that shows refraction in action.

Ruler Changes Size Science Experiment - Observe how the size of an object changed when viewed through different liquids.

I hope you enjoyed the experiment. Here are some printable instructions:

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Cool Light Refraction Science Experiment - Arrow Changes Direction!

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Watch light refraction in action when the arrow changes direction in this easy science experiment for kids