Mole (mol)

The Mole (mol) is the base unit of amount of substance of a system in the International System (SI) of Units that may be atoms, molecules, ions, electrons, other particles, or specified groups of such particles. (e.g., the molecular weight of calcium is 40, and one mole of calcium equals 40 grams. It can also be defined as the quantity of chemical that contains 6.02 x 1023 (Avogadro’s number) atoms or molecules of that substance.)

Reference Definition by NIST: The mole, symbol mol, is the SI unit of amount of substance. One mole contains exactly 6.022 140 76 x 1023 elementary entities. This number is the fixed numerical value of the Avogadro constant, NA, when expressed in the unit mol-1 and is called the Avogadro number. The amount of substance, symbol n, of a system is a measure of the number of specified elementary entities. An elementary entity may be an atom, a molecule, an ion, an electron, any other particle or specified group of particles.