Physical and Chemical Changes of Matter

Front

What is a chemical change?

Back

A process where substances combine or break apart to form new substances, often accompanied by energy changes.

Front

What are some clues that indicate a chemical change has occurred?

Back

Color change, temperature change, sound production, gas production, odor production, and formation of a precipitate.

Front

Are chemical changes usually reversible?

Back

No, chemical changes are usually irreversible.

Front

What is a physical change?

Back

A change in which the form of matter is altered but not its chemical composition.

Front

In a physical change, does the substance have the same chemical composition before and after the change?

Back

Yes, the chemical composition remains the same.

Front

What is an example of a physical change?

Back

Melting ice, boiling water, or breaking a glass.

Front

What is an example of a chemical change?

Back

Burning wood, rusting iron, or baking a cake.

Front

What happens to energy during a chemical change?

Back

Energy is either absorbed or released.

Front

What is a precipitate?

Back

A solid that forms and settles out of a liquid mixture during a chemical reaction.

Front

What does it mean if a reaction produces gas?

Back

It indicates a chemical change has occurred.