Statement that, under the same conditions of temperature and pressure , equal volumes of different gas es contain an equal number of molecules (see Avogadro's number ).
First proposed by the Italian scientist Amedeo Avogadro (1776–1856) in 1811, it became accepted с 1860. From the law, it follows that the volume occupied by one mole of gas (at standard conditions of 32 kF [0 kC] and 1 atmosphere of pressure) is the same for all gases (0.791 cubic feet [22.4 litres]).