Quantum Numbers

Very soon one after the other the gas laws of Joseph Louis Gay-Lussac and that of Joseph Louis Proust's law of definite proportions came into being. In this period too came the hypothesis of Amedeo Avogadro, an Italian chemist, about the number of molecules in a volume of gas. To Dalton's theory that the atoms of a single element have the same weight, Avogadro, in 1811, added the idea that one quart (or other volume) of a gas has the number of molecules which are exactly same as that of any other gas with an equal volume if both are allowed to rest at the same temperature and pressure.