When alcohol evaporates, the liquid alcohol molecules absorb energy from their surroundings and gain enough kinetic energy to overcome the intermolecular forces holding them together in the liquid state. As a result, the alcohol molecules break away from the liquid and enter the gas phase. This process is known as vaporization.

During vaporization, the chemical composition of the alcohol molecules does not change. They are still composed of the same atoms (carbon, hydrogen, and oxygen) in the same proportions. However, the physical state of the alcohol changes from a liquid to a gas.

A change in physical state is considered a physical change. However, in this case, the process of vaporization is accompanied by a chemical change. This is because the intermolecular forces holding the alcohol molecules together in the liquid state are broken apart. These intermolecular forces are considered chemical bonds, so breaking them apart is considered a chemical change.

Therefore, evaporating alcohol is both a physical change and a chemical change.