Chemical changes involve the formation of new substances with different chemical properties, while physical changes only involve a change in the physical appearance or state of a substance. Chemical changes are irreversible and involve chemical reactions, while physical changes are reversible and do not involve any changes in the chemical composition of a substance. Examples of chemical changes include burning, rusting, and digestion, while examples of physical changes include melting, freezing, and evaporating. Both types of changes involve energy changes, but in physical changes, energy is usually transferred in the form of heat, while in chemical changes, energy is required or released during a chemical reaction.
