What is the X in X-mas?
evaporation e·vap·o·ra·tion (ĭ-vāp'ə-rā'shən)
A change from liquid to vapor form.
Loss of volume of a liquid by conversion into vapor. Also called volatilization.
The change of a liquid into a vapor at a temperature below the boiling point. Evaporation takes place at the surface of a liquid, where molecules with the highest kinetic energy are able to escape. When this happens, the average kinetic energy of the liquid is lowered, and its temperature decreases.