Nonvolatile substances are those molecules that will not evaporate quickly. Boiling point is the temperature at which the vapor pressure of the liquid equals atmospheric pressure. At this point, more liquid molecules have a higher kinetic energy and therefore more likely to escape into the gas state. Melting point is the temperature at which the vapor pressure of the liquid equals the vapor pressure of the solid. At this point, more solid molecules have more kinetic energy and therefore are more likely to escape into the liquid state. Intermolecular bonds are those bonds?