The boiling point of an element is that temperature at which the element changes state from a liquid to a gas when at atmospheric pressure. Since, at boiling point, the saturated vapour pressure of a liquid equals the pressure of the atmosphere, the boiling point varies with pressure. Boiling point is quoted in K, Kelvin, an absolute scale. To convert to ░C, Celsius, add 273.15. It will be noted that boiling point generally increases with atomic weight, and that the transition metals have very high boiling points. Some elements like arsenic and boron sublime, that is they turn directly from solid to gas without liquefying, (except under high pressure). Tungsten has the highest boiling point at 5933K, whilst helium, being inert and with extremely low inter-atomic forces, is the easiest to vaporises, boiling at just 4.2K (4.2 degrees above absolute zero temperature), or -269░C. Hydrogen, nitrogen, oxygen, fluorine, chlorine and all the noble gases are the only elements gaseous at room temperature.
