Avogadro, Armedeo (1776-1856)

The Italian scientist after which is named the Avogadro's Law, viz,. "equal volumes of different gases, pressure and temperature being equal, contain the same number of molecules"; or, "equal volumes of gases or vapours contain the same number of molecules".

He proposed a correct molecular explanation for Gay-Lussac's law of combining volumes. His work provided a simple way to determine atomic weights and molecular weights of gases.