Identify Chemical and Physical Changes

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.

A chemical change is a change that results in the formation of new chemical substances. It involves a chemical reaction and changes the chemical composition of the substance. Examples include burning, rusting, and souring.

Melting ice is a physical change.

Freezing water is a physical change.

The chemical composition remains the same during a physical change.

The chemical composition changes during a chemical change, resulting in new substances.

An example of a chemical change is souring milk.

An example of a physical change is cutting bread.

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

Indicators of a physical change include changes in state (solid, liquid, gas) and changes in shape or size.