mole 

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 76×1023 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:
The formulation of this definition was agreed upon by the 26th CGPM in November 2018 with effect from 20 May 2019.
Source:
BIPM, The International System of Units, SI Brochure, 9th ed. (2019), p. 134 [Terms] [Book]
Citation: 'mole' in IUPAC Compendium of Chemical Terminology, 5th ed. International Union of Pure and Applied Chemistry; 2025. Online version 5.0.0, 2025. https://doi.org/10.1351/goldbook.M03980 RIS BibTex EndNote
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Last revised: March 30, 2020