Chemical and Physical Changes

Front

What is a physical change?

Back

A physical change is a change that affects one or more physical properties of a substance without altering its chemical composition. Examples include melting, freezing, and boiling.

Front

What is a chemical change?

Back

A chemical change is a change that results in the formation of new chemical substances. It involves a chemical reaction and includes processes like burning, rusting, and digestion.

Front

What happens to butter when it melts?

Back

When butter melts, it undergoes a physical change from solid to liquid, but its chemical structure remains the same.

Front

What happens to water when it is heated to steam?

Back

When water is heated to steam, it undergoes a physical change from liquid to gas, but its chemical composition (H2O) remains unchanged.

Front

What is an example of a chemical change?

Back

Burning toast is an example of a chemical change because it produces new substances (carbon and ash) and cannot be reversed.

Front

What are atoms?

Back

Atoms are the tiny building blocks of all matter. They are the smallest units of an element that retain the properties of that element.

Front

Which of the following has matter?

Back

All of the above (basketball, the sun, you) have matter because they occupy space and have mass.

Front

What is the difference between a physical change and a chemical change?

Back

A physical change does not change the substance's chemical identity, while a chemical change results in the formation of new substances.

Front

Can a physical change be reversed?

Back

Yes, many physical changes can be reversed, such as freezing and melting water.

Front

Can a chemical change be reversed?

Back

Most chemical changes cannot be easily reversed, such as burning wood to ash.