Physical and Chemical 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 dissolving.

Front

What is a chemical change?

Back

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

Front

What happens to the state of matter when heat is added?

Back

When heat is added to a substance, it can change from a solid to a liquid (melting) or from a liquid to a gas (evaporation).

Front

What happens to the state of matter when heat is removed?

Back

When heat is removed from a substance, it can change from a gas to a liquid (condensation) or from a liquid to a solid (freezing).

Front

What is an example of a liquid turning into a gas?

Back

An example of a liquid turning into a gas is water boiling and turning into steam.

Front

Which materials are likely to rust?

Back

Materials made of iron or steel are likely to rust when exposed to moisture and oxygen.

Front

True or False: The state of matter can change depending on whether heat is added or removed.

Back

False. The state of matter can change when heat is added or removed.

Front

What is melting?

Back

Melting is the process where a solid turns into a liquid when heat is applied. An example is heating a block of ice until it turns to water.

Front

What is dissolving?

Back

Dissolving is the process where a substance (like sugar) mixes with a liquid (like water) to form a solution.

Front

What happens to sugar in hot water over time?

Back

The sugar will dissolve in the hot water, spreading evenly throughout the liquid.