https://doi.org/10.1351/goldbook.M03970
Amount of entities of a @S05744@ divided by the mass of the @S05746@.
Sources:
Green Book, 2nd ed., p. 42 [Terms] [Book]
PAC, 1996, 68, 957. (Glossary of terms in quantities and units in Clinical Chemistry (IUPAC-IFCC Recommendations 1996)) on page 982 [Terms] [Paper]