Language:enStatus: Standard
Term: mole
Symbol: mol
Definition: SI unit of amount of substance, equal to the amount of substance of a system that contains 6,022 140 76 × 1023 specified elementary entities

Note 1 to entry: The definition in the SI Brochure is: "The mole, symbol mol, is the SI unit of amount of substance. One mole contains exactly 6,022 140 76 × 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."

Note 2 to entry: The definition of the mole in IEV 112-02-09:2010-01 fixed the value of the molar mass of carbon 12, M(12C), as exactly equal to 0,012 kg/mol. According to the current definition of the mole, M(12C) is no longer known precisely and has to be determined experimentally.

Note 3 to entry: The mole is one of the seven SI base units: second (s), metre (m), kilogram (kg), ampere (A), kelvin (K), mole (mol) and candela (cd).

Publication date:2020-12
SourceSI Brochure, 9th edition, 2019, 2.3.1, modified – The definition in the SI Brochure has been revised to comply with the IEV rules. Notes 1 to 3 to entry have been added.
Internal notes:
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