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. It involves a chemical reaction and changes the composition of the original substance. Examples include burning, rusting, and cooking.

Front

Is burning wood a physical or chemical change?

Back

Burning wood is a chemical change because it produces new substances such as ash and smoke.

Front

Is freezing juice a physical or chemical change?

Back

Freezing juice is a physical change because it changes the state of the juice from liquid to solid without altering its chemical composition.

Front

What happens to the molecules during a physical change?

Back

During a physical change, the molecules may change their arrangement or state (solid, liquid, gas) but their chemical structure remains the same.

Front

What happens to the molecules during a chemical change?

Back

During a chemical change, the molecules rearrange to form new substances with different chemical properties.

Front

Give an example of a physical change.

Back

An example of a physical change is ice melting into water.

Front

Give an example of a chemical change.

Back

An example of a chemical change is iron rusting when it reacts with oxygen.

Front

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

Back

The main difference is that a physical change does not alter the chemical composition of a substance, while a chemical change does.

Front

Can a physical change be reversed?

Back

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