Vaporizing alcohol is a physical change. During vaporization, the alcohol changes from a liquid to a gas state without altering its chemical composition. The bonds between the alcohol molecules remain intact, and no new substances are formed. As the temperature of the alcohol increases, its molecules gain energy and overcome the intermolecular forces holding them together, allowing them to escape into the air. This change is reversible, meaning that the alcohol vapor can be condensed back into a liquid by cooling it down.