Diffused or the gaseous form of substances, which are normally in the solid or liquid state at room temperature and pressure. Evaporation is the process where liquids are transformed into gas or vapors. Vapors can be changed back into the solid or liquid state through pressurization or temperature drops. Solvents with low boiling points are called volatile and easily changes to the vapor state. Examples are benzene, alcohol, mercury, and toluene.