of the substance expressed in daltons.

Since 2019, the mole has been redefined in the SI as the amount of any substance containing exactly entities, fixing the numerical value of the Avogadro constant when expressed in the unit mol^-1, but because the dalton is still defined in terms of the experimentally determined mass of a carbon-12 atom, the numerical equivalence between the molar mass of a substance and the average mass of an entity