A phase change is a physical change in the state of a substance, such as from a solid to a liquid or a liquid to a gas. Phase changes occur when the temperature or pressure of a substance is changed.
Chemical changes, on the other hand, occur when the chemical composition of a substance is changed. Chemical changes can occur when two or more substances react to form a new substance, or when a single substance decomposes to form two or more new substances.
Therefore, a chemical change does not occur when a substance changes phase.
