SI amount of substance unit. symbol: mol. It is one
of the base units in SI. It is defined as follows: the Mole is the
amount of substance of a system which contains as many elementary entities
as there are atoms in 0.012 Kilograms of carbon 12. Note that, when this
UnitOfMeasure is used, the elementary entities must be specified - they
may be atoms, molecules, ions, electrons, etc. or groups of such
particles.
![[tree]](../../img/tree.gif)