mole (mol) The base unit of amount of substance in the SI system of units. One mole equals the amount of substance that contains as many elementary units as there are atoms in 0.012 kg of carbon-12. The elementary units may be atoms, molecules, ions, radicals, electrons, etc., and must be specified. 1 mole of a compound has a mass equal to its relative molecular mass expressed in grams. The number of elementary units in 1 mole is called the Avogadro constant (formerly known as Avogadro's number). Related categories PHYSICAL CHEMISTRY UNITS Also on this site: Encyclopedia of Alternative Energy & Sustainable Living Encyclopedia of History Transport Concepts & Designs (partner site) |