1.2 The gas laws
Key points (a) The perfect gas law, a limiting law valid in the limit of zero pressure, summarizes
Boyle’s and Charles’s laws and Avogadro’s principle. (b) The kinetic theory of gases, in which
molecules are in ceaseless random motion, provides a model that accounts for the gas laws and a
relation between average speed and temperature. (c) A mixture of perfect gases behaves like a single
perfect gas; its components each contribute their partial pressure to the total pressure.