Chemical and Physical Changes in Matter

Front

What is a physical change?

Back

A physical change is a change in which no new substances are formed. Examples include melting, freezing, and dissolving.

Front

What is a chemical change?

Back

A chemical change is a change that results in the formation of new substances. Examples include burning, rusting, and tarnishing.

Front

What happens to chocolate when it melts?

Back

Melting chocolate is a physical change because it changes from solid to liquid but remains chocolate.

Front

What occurs when sugar dissolves in water?

Back

When sugar dissolves in water, it is a physical change because the sugar can be recovered by evaporating the water.

Front

What is an example of a chemical change?

Back

An example of a chemical change is wood burning, which produces ash and smoke, creating new substances.

Front

What is a precipitate?

Back

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

Front

Why does a precipitate form when two solutions are mixed?

Back

A precipitate forms because a chemical change occurs, resulting in a new substance.

Front

What is copper tarnishing an example of?

Back

Copper tarnishing is an example of a chemical change, as it results in the formation of a new substance (copper oxide).

Front

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

Back

A physical change does not create new substances, while a chemical change does.

Front

Can physical changes be reversed?

Back

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