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 changing 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 making or breaking bonds between atoms. Examples include burning, rusting, and cooking.

Front

Can a physical change be reversed?

Back

Yes, many physical changes can be reversed. For example, ice can melt into water and then freeze back into ice.

Front

Can a chemical change be reversed?

Back

No, chemical changes usually cannot be reversed easily. For example, burning wood creates ash and smoke, which cannot be turned back into wood.

Front

What happens to the molecules during a physical change?

Back

During a physical change, the arrangement of molecules may change, but the molecules themselves remain the same.

Front

What happens to the molecules during a chemical change?

Back

During a chemical change, the molecules are rearranged to form new substances with different 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.

Front

What is the difference between a physical and chemical change?

Back

The main difference is that a physical change does not create a new substance, while a chemical change does.

Front

What is an indicator of a chemical change?

Back

Indicators of a chemical change include color change, temperature change, gas production, and the formation of a precipitate.