https://doi.org/10.1351/goldbook.M03980

The mole, symbol mol, is the SI unit of amount of substance. One mole contains exactly 6.022 140 76 x 10^{23} elementary entities. This number is the fixed numerical value of the Avogadro constant, N_{A}, when expressed in the unit mol^{-1} and is called the Avogadro number.

The amount of substance, symbol The formulation of this definition was agreed upon by the 26

BIPM, The International System of Units, SI Brochure, 9