Temperature at which the vapor pressure of a liquid is equal to the ambient pressure – thus, the boiling point depends on pressure. A liquid may change to a gas at temperatures below the boiling point by evaporationProcess in which atoms or molecules in a liquid state (or solid state if the substance sublimes) gain sufficient energy to enter the gaseous state.. However, evaporation is a surface phenomenon where only molecules located near the gas/liquid surface may evaporate. Boiling is a bulk process where, at the boiling point, molecules anywhere in the liquid may be vaporized, resulting in the formation of vapor bubbles.
Some or all content above used with permission from J. H. Wittke.