Question

History of Avogadro's number and where it came from?

Answer 1

Answer:

Origin of the concept

The Avogadro constant is named after the Italian scientist Amedeo Avogadro, who, in 1811, first proposed that the volume of a gas (at a given pressure and temperature) is proportional to the number of atoms or molecules regardless of the nature of the gas.

Answer 2

Answer:

Avogadro proposed his hypothesis in 1811. At that time there was no data at all on the number of paticles in a mole, or an agreement on any atomic weights or the standard. The first measurements which could give an approximate value for Avogadro's number were observations of brownian motion by Robert Brown in 1827.