Physical vs. Chemical Changes

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.

A chemical change is a change that results in the formation of one or more new substances with different properties. Examples include burning, rusting, and baking.

In a physical change, the substances retain their original properties and can often be separated back into their original forms.

In a chemical change, the original substances are transformed into new substances with different properties, and they cannot be easily separated back into their original forms.

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

An example of a chemical change is burning wood, which produces ash and smoke.

A mixture is a combination of two or more substances where each substance retains its own properties and can be separated by physical means.

A new substance is a material that is formed as a result of a chemical change, having different properties from the original substances.

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

Rusting of iron is a chemical change because it forms a new substance, iron oxide.