Physical and chemical changes

A chemical change is a process where one or more substances are transformed into new substances with different properties.

A physical change is a change that affects one or more physical properties of a substance without altering its chemical composition.

Examples include fizzing, foaming, burning, and exploding fireworks.

An example is salt dissolving in water.

During a chemical change, new substances are formed, and the original substances lose their properties.

During a physical change, the substance may change in form or appearance, but its chemical composition remains the same.

A physical change does not create a new substance, while a chemical change does.

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

Indicators include changes in state (solid, liquid, gas), shape, or size without a change in chemical composition.

Most chemical changes are not easily reversible, unlike physical changes which often can be reversed.