Summary:

  • As a liquid is heated, the average kinetic energy of its particles increases.
  • The rate of evaporation increases as more and more molecules are able to escape the liquid’s surface into the vapor phase.
  • Eventually a point is reached when the molecules all throughout the liquid have enough kinetic energy to vaporize.
  • At this point the liquid begins to boil.
  • The boiling point is the temperature at which the vapor pressure of aLiquid is equal to the external pressure.
  • Compare how atmospheric pressure, vapor pressure and boiling point relate in this simulation.
Select from the frequently asked questions below