Physical and Chemical Changes

Front

What is a physical change?

Back

A physical change is a change in the form or appearance of a substance, but it does not change the substance's 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 molecules in a solid when it melts?

Back

When a solid melts, its molecules gain energy and move apart, transitioning into a liquid state.

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

What state of matter always keeps its shape?

Back

Solid.

Front

What is an example of freezing?

Back

An example of freezing is water turning into ice when the temperature drops below 0°C.

Front

What is an example of condensation?

Back

An example of condensation is water vapor in the air turning into droplets on a cold glass.

Front

What is rusting?

Back

Rusting is a chemical change that occurs when iron reacts with oxygen and moisture, forming iron oxide.

Front

What is evaporation?

Back

Evaporation is the process by which liquid turns into gas, usually at the surface of the liquid.

Front

What is sublimation?

Back

Sublimation is the process where a solid changes directly into a gas without becoming a liquid first, like dry ice turning into carbon dioxide gas.