Chemical changes involve the transformation of the molecules in a substance to form new substances with different chemical properties. Physical changes, on the other hand, involve alterations in the appearance or state of a substance without changing its chemical composition. Examples of physical changes include changes in state (such as melting or freezing) or changes in shape, size, or color. Chemical changes often involve the release or absorption of energy, such as heat or light, while physical changes usually do not involve the exchange of energy. Both types of changes can be reversible or irreversible, depending on the conditions involved.
