What is Avogadro's number?

Avogadro's number (sometimes referred to as Avogadro's constant or law) is chemical/physics mathematical term that describes how many units (e.g. electrons, atoms, molecules) that can be found in one mole (molecular weight x one gram. For instance one mole of carbon (molecular weight 12) x 1 gram is 12 grams,) of any substance and is equal to 6.022140857 × 1023.

The 1925 Nobel Prize winner Jean Perrin proposed the naming of the constant after Amedeo Avogadro in 1911.

Avogadro was the first to propose that the volume of a gas (at a given temperature and pressure) was proportional to the number of atoms or molecules regardless of the nature of the gas.

It also provides the relation between other physical constants and properties.