Chemical changes involve the formation of new substances with different chemical properties, while physical changes do not result in the formation of new substances. Chemical changes involve the rearrangement of atoms to form new molecules, resulting in a change in chemical composition, while physical changes only involve a change in the physical state or appearance of a substance. Chemical changes are often irreversible, while physical changes can usually be reversed by changing the conditions that caused the change. Both chemical and physical changes involve a transfer of energy, but the energy transfer in a chemical change is usually greater.
