# data[].attributes.body
Visit my bookshelf in Benchmark with books about matter. There are also books about forces...What do forces have to do with matter?

# data[].attributes.body
You learn by doing things, right? Go to the library and check out this book to try some experiments with matter! Don't forget to check with your grow-ups before you try anything. Come back to class and share with us! What did you try? What did you learn?

# data[].attributes.body
This article will help you better understand the difference between physical and chemical changes. An example of a chemical change is oxidation. Iron and copper are common metals that can oxidize. Can you think of another statue like the lion in the image that is oxidized copper?

# data[].attributes.attachment_link.readable_text
Matter is capable of undergoing changes, which are classified as either physical or chemical. Physical changes in matter are reversible: An ice cube can melt into liquid water, and then the liquid water can be frozen back into an ice cube. Chemical changes, on the other hand, are not reversible: A log burned in a fire turns to ashes, but the ashes cannot be changed back into a log.

What Is a Physical Change?

In a physical change, the material involved in the change is structurally the same before and after the change. Types of some physical changes are texture, shape, temperature, and a change in the state of matter. A change in the texture of a substance is a change in the way it feels. For instance, a block of wood may feel rough when you run your finger across it but rubbing the wood with sandpaper smooths the surface so it no longer feels rough. The wood itself has not changed during sanding to become a new material, only the texture of the surface changed. A piece of metal may be heated in a fire until it glows, but the metal is the same material before heating and after cooling. Similarly, when a material changes phase, it only changes physically; the substance is still the same. Think about ice melting into water, and then water being heated up and turning into steam. The chemical structure of water is the same whether it is a solid (ice), liquid, or gas (steam).

What Is a Chemical Change?

A chemical change occurs when the composition of a substance is changed, which requires the breaking and forming of chemical bonds during a chemical reaction. This results in the rearranging of atoms in substances to form the products of a chemical reaction, which are brand new molecules that cannot be easily reverted back to their original state.

Sometimes it is difficult to tell if a chemical reaction has taken place. To help determine whether there has been a reaction, chemists consider the basic indicators that a reaction has occurred, such as a change in temperature, a change in color, the development of an odor, the formation of a precipitate, or the formation of a gas.

In a chemical alteration, the temperature change occurs as a result of the breaking or formation of chemical bonds. When the chemical bonds of the reactants are broken, sometimes excess energy is released, causing heat to be discharged, and leading to an increase in temperature. Alternatively, a reaction may require energy from the environment in order to take place, causing heat to be absorbed, and leading to a decrease in temperature. Burning wood is an example of a reaction that releases excess energy as heat. A chemical cold pack in a first aid kit is an example of a chemical reaction that absorbs heat energy resulting in cooling.

An example of a color change signaling a chemical reaction can be observed when iron reacts with oxygen to produce iron oxide, such as when an iron nail is left outside, and it develops a reddish-brown rust.

Rotting food is an example of odor development as a result of a chemical change. When food is left out for too long, or it reaches its expiration date, it eventually spoils, often producing a foul odor in its rotten state. This is because of chemical reactions that take place as the food begins to break down and go bad, which leads to the formation of new substances that have unique smells associated with them.

Another common sign of a chemical reaction is the formation of a precipitate. This happens when chemicals dissolved in a solution are mixed together and an insoluble solid, known as a precipitate, forms in the liquid mixture. The creation of a new, solid substance from two liquid substances indicates that a reaction has taken place and altered the original substances.

A common chemical reaction is the mixing of vinegar and baking soda. When these two household chemicals are mixed together, it immediately starts bubbling and foaming. The bubbles are a release of carbon dioxide gas, a product of the chemical reaction between the baking soda and vinegar.

Remember that the difference between a physical reaction and chemical reaction is that a chemical reaction cannot be easily reversed, if at all.

Chemical Change or Physical Change?

Sometimes it is difficult to determine whether a change is physical or chemical. For example, think about dissolving table salt (sodium chloride) into liquid water. The solid table salt is added to the water and disappears. This dissolution is easily identified as a physical change, because if the water is allowed to evaporate, the salt remains after all the water has evaporated, meaning it has not been permanently altered. However, table salt is an ionic compound. Ions are negatively or positively charged atoms or molecules (because of the loss or gain of an electron). When ionic compounds are added to water, they dissociate or break apart into ions. In the case of table salt, it dissociates into sodium ions (positive) and chloride ions (negative) in the water, which would seem to be a chemical change. However, scientists do not consider this to be a chemical change because the solid table salt remains after the water is evaporated. The table salt dissociated, but the atoms recombine into the same arrangement once the water is removed.

Another example of a change that is difficult to identify as either physical or chemical is when two or more metals are mixed together when molten to form an alloy; an alloy is a metal that has different properties from the metals that were mixed together to make it. A common alloy is brass, which can be found on decorative hinges and knobs, as well as on musical instruments like trumpets, trombones, and saxophones. Brass is made up of about 60 percent copper and 40 percent zinc, but brass has different properties than either copper or zinc alone. However, even though the properties of brass are different from copper and zinc, brass is not made via a chemical reaction. The copper and zinc atoms are both in brass, but they do not chemically bond together. As a result, brass represents a physical change instead of a chemical change.

Remember that a physical change is a change in properties such as texture, shape, or state, while a chemical change represents the formation of a new substance after atoms are rearranged in a chemical reaction.

# data[].attributes.attachment_link.title
Changes in Matter: Physical vs. Chemical Changes | National Geographic Society

# data[].attributes.attachment_link.description
Matter is capable of undergoing changes, which are classified as either physical or chemical. Physical changes in matter are reversible: An ice cube can melt into liquid water, and then the liquid water can be frozen back into an ice cube.

# data[].attributes.body
Take a look at this ebook in Epic to see some fun ways to experiment with matter. Which investigation looks the the most fun and is something you would like to try at home (with your grown-up's permission, of course)? What is something new you learned from one of the investigations?

# data[].attributes.attachment_link.readable_text
Built on a collection of 40,000+ popular, high-quality books from 250+ of the world's best publishers, Epic safely fuels curiosity and reading confidence for kids 12 and under.

Get Started

# data[].attributes.attachment_link.keywords[]
online access fun thousands children great kids ebooks books

# data[].attributes.attachment_link.description
Built on a collection of 40,000+ popular, high-quality books from 250+ of the world's best publishers, Epic safely fuels curiosity and reading confidence for kids 12 and under. Get Started

# data[].attributes.body
Start here if you don't know what matter or properties are. Read some of the basic ideas of matter. Can you share a definition of matter and explain what it means?

# data[].attributes.attachment_link.readable_text
Matter exists in several different forms, called states. The three most familiar states are solid, liquid, and gas.

Rocks, books, desks, and balls are examples of solids. Matter in the solid state has a set size and shape. A solid's size and shape do not change easily. For example, when a person moves a book from a smaller to a bigger box, the book looks the same.

Milk, orange juice, and water are examples of liquids. In the liquid state matter has a set size, or amount. However, its shape depends on its container. For example, milk changes shape when a person pours it from a carton into a glass. But the amount of milk stays the same.

The air and the helium used to fill balloons are examples of gases. Matter in the gaseous state does not have either a set size or a set shape. It can expand to fill a large container, or it can be squeezed into a smaller container.

Matter can change from one state to another. This happens when a substance is cooled or heated to a particular point. For example, heat causes liquid water to evaporate, or turn into water vapor-a gas. The temperature at which a liquid turns into a gas is called its boiling point. The water vapor will change back into liquid when cooled. If it is cooled enough, water will freeze and become a solid. The temperature at which a liquid becomes a solid is called its freezing point. That same temperature can be considered the melting point if the temperature is increasing and causes a solid to become a liquid. For example, liquid water turns to a solid form-ice-when it is cooled to 32 °F (0 °C). The melting point for ice is the same temperature. Different types of matter have different boiling, melting, and freezing points.

# data[].attributes.attachment_link.description
Anything that takes up space is called matter. Air, water, rocks, and even people are examples of matter. Different types of matter can be described by their mass. The mass...

# data[].attributes.headline
Info Graphic-Chemical or Physical Properties

# data[].attributes.subject
Info Graphic-Chemical or Physical Properties

# data[].attributes.body
How can you determine if a property is chemical or physical? This info graphic flow chart can help you decide.

# data[].attributes.attachment_link.readable_text
Matter can be identified and described by various characteristics. The flowchart shows how to determine if such characteristics are chemical or physical properties. Physical properties can be further divided into intensive and extensive properties.

© Encyclopædia Britannica, Inc.

# data[].attributes.attachment_link.description
Matter can be identified and described by various characteristics. The flowchart shows how to determine if such characteristics are chemical or physical properties. Physical properties can be further divided into intensive and extensive properties.

# data[].attributes.body
One property is the state that matter is in. This info graphic describes the differences between the states of matter with models to demonstrate each one. Can you explain one of the states of matter to a partner?

# data[].attributes.attachment_link.readable_text
To

Recipients Please enter a valid email address.

To share with more than one person, separate addresses with a comma

From

Sender Name Please enter your name.

Sender Email Please enter a valid email address.

# data[].attributes.attachment_link.description
Animals Arts and Literature Earth and Geography History Life Processes Living Things (Other) Philosophy and Religion Plants Science and Mathematics Society Sports and Recreation Technology

# data[].attributes.body
This video discusses how you can use properties to find an object you want. Properties covered include MAGNETISM and MALIABILITY. How have you used properties to find something you need? (TIP: She speaks quickly so you may want to adjust the playback speed to .75 in the video settings.)

# data[].attributes.attachment_link.title
What's My Property: Crash Course Kids #35.2

# data[].attributes.body
If you enjoyed the Properties of Matter video from Crash Course <-- or need more information to understand properties of matter better, here is their entire playlist about matter. After watching the playlist, what do have a better understanding about or what are some other properties you learned about?

# data[].attributes.attachment_link.description
Share your videos with friends, family, and the world

# data[].attributes.body
This video clip explains the property known as DENSITY by making observations about gasses. Do you think liquids also have different densities?

# data[].attributes.attachment_link.title
Properties of Matter | Science Lesson for Kids | Grades 3-5

# data[].attributes.attachment_link.description
Want to learn about the properties of matter like density and solubility? Watch our fun video on matter for kids in 3rd, 4th and 5th grade!

# data[].attributes.headline
What is the vocabulary for changing states of matter?

# data[].attributes.subject
What is the vocabulary for changing states of matter?

# data[].attributes.body
Draw a diagram like this in your science notebook and decide what each process for changing states of matter is called. TIP: CONDENSATION is one of the answers.