physical change vs. chemical change

physical change vs. chemical change: What’s the difference?

In chemistry, physical changes are those that affect the physical properties of a substance (such as size or shape). Physical changes are usually reversible. Chemical changes are usually irreversible chemical reactions that result in at least one new substance. For example, water freezing is a physical change, while metal rusting is a chemical change.

physical change

[fiz-i-kuhl cheynj] / ˈfɪz ɪ kəl ˈtʃeɪndʒ /

noun

Chemistry.

a usually reversible change in the physical properties of a substance, as size or shape.

Freezing a liquid is a physical change.

chemical change

[kem-i-kuhl cheynj] / ˈkɛm ɪ kəl ˈtʃeɪndʒ /

noun

Chemistry. a usually irreversible chemical reaction involving the rearrangement of the atoms of one or more substances and a change in their chemical properties or composition, resulting in the formation of at least one new substance.

The formation of rust on iron is a chemical change.