mean substance rate, \(\frac{\Delta n}{\Delta t}\)

https://doi.org/10.1351/goldbook.M03786
The @A00297@ of a specified component changed in or moved to or from a system divided by the time during which the component was changed or moved. This kind of quantity usually should be preferred to @M03784@ or @M03787@.
Source:
PAC, 1979, 51, 2451. (Quantities and Units in Clinical Chemistry) on page 2475 [Terms] [Paper]