Physical/Chemical Changes

A physical change is a change that affects one or more physical properties of a substance without altering its chemical composition. Examples include changes in state (like melting or freezing), shape, or size.

A chemical change is a change that results in the formation of new chemical substances. It involves a chemical reaction and the rearrangement of atoms. Examples include rusting of iron and burning of wood.

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 physical change is ice melting into water.

An example of a chemical change is the reaction of vinegar and baking soda, which produces carbon dioxide gas.

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

Rusting is an example of a chemical change, as it involves the reaction of iron with oxygen in the presence of moisture to form iron oxide.

Dissolving sugar in water is a physical change because the sugar can be recovered by evaporating the water.

A physical change does not alter the chemical composition of a substance, while a chemical change results in the formation of new substances.