Amount of substance is a base dimension in the International System of Units. The SI unit of amount of substance is the mole, which is defined as an amount of a substance that contains as many elementary entities as there are atoms in 12 grams of carbon-12 (14th CGPM, 1971).

When the mole is used, the elementary entities must be specified: atoms, molecules, ions, electrons, other particles, or any specified group of particles. In the Units package, use modifiers and/or attachments in parentheses to indicate the entities.

Maple knows the units of amount of substance listed in the following table.

An asterisk ( * ) indicates the default context, an at sign (@) indicates an abbreviation, and under the prefixes column, SI indicates that the unit takes all SI prefixes, IEC indicates that the unit takes IEC prefixes, and SI+ and SI- indicate that the unit takes only positive and negative SI prefixes, respectively.  Refer to a unit in the Units package by indexing the name or symbol with the context, for example, mole[SI] or mol[SI]; or, if the context is indicated as the default, by using only the unit name or symbol, for example, mole or mol.

The unit of amount of substance is defined as follows.

A mole is defined as approximately $6.0221367\times {10}^{23}$ elementary entities.

$\mathrm{convert}\left('\mathrm{mole}'\,'\mathrm{dimensions}'\,'\mathrm{base}'\right)$

$\mathrm{amount\_of\_substance}$

$\mathrm{convert}\left(337.29\,'\mathrm{units}'\,\frac{'J'}{'\mathrm{mol}\left(\mathrm{carbon12}\right)'}\,\frac{'\mathrm{kg}'}{'\mathrm{mol}\left(\mathrm{carbon12}\right)'}\,'\mathrm{energy}'\right)$

$3.752857374\times {10}^{\mathrm{-15}}$

$\mathrm{convert}\left(337.29\,'\mathrm{units}'\,\frac{'J'}{'\mathrm{mol}\left(\mathrm{carbon12}\right)'}\,\frac{'\mathrm{kg}'}{'\mathrm{mol}\left(\mathrm{carbon13}\right)'}\,'\mathrm{energy}'\right)$

$3.752857374\times {10}^{\mathrm{-15}}$

$\mathrm{convert}\left(337.29\,'\mathrm{units}'\,\frac{'J'}{'\mathrm{mol}\left(\mathrm{carbon12}\right)'}\,'\mathrm{kg}'\,'\mathrm{energy}'\,'\mathrm{symbolic}'\right)$

$6.231766181\times {10}^{\mathrm{-39}}$