text: Macroscopically, the ideal gas law states that, for an ideal gas, the product of pressure  and volume  is proportional to the product of amount of substance  and absolute temperature :
  where  is the molar gas constant (). Introducing the Boltzmann constant as the gas constant per molecule  (being N the Avogadro constant) transforms the ideal gas law into an alternative form:
  where  is the number of molecules of gas.