Editing Pressure (section)

===Vapour pressure===
{{main|Vapour pressure}}
Vapour pressure is the pressure of a [[vapour]] in [[thermodynamic equilibrium]] with its condensed [[Phase (matter)|phase]]s in a closed system. All liquids and [[solid]]s have a tendency to [[evaporate]] into a gaseous form, and all [[gas]]es have a tendency to [[condense]] back to their liquid or solid form.

The [[atmospheric pressure]] [[boiling point]] of a liquid (also known as the [[normal boiling point]]) is the temperature at which the vapor pressure equals the ambient atmospheric pressure. With any incremental increase in that temperature, the vapor pressure becomes sufficient to overcome atmospheric pressure and lift the liquid to form vapour bubbles inside the bulk of the substance. [[liquid bubble|Bubble]] formation deeper in the liquid requires a higher pressure, and therefore higher temperature, because the fluid pressure increases above the atmospheric pressure as the depth increases.

The vapor pressure that a single component in a mixture contributes to the total pressure in the system is called [[partial pressure|partial vapor pressure]].