Evaporation

Evaporation, escape of molecules from the surface of a liquid such that they attain a gaseous state. Only those molecules with sufficient kinetic energy (i.e., heat) are able to overcome the cohesive forces holding the liquid together and escape from the surface. This leaves the remaining molecules with a lower average kinetic energy and hence a lower temperature. In an unenclosed space, the entire body of the liquid can eventually evaporate, which means that the matter will have changed from a liquid to a gas.