Derived kind-of-quantity defined as the amount of substance (n) of a component specified by an elementary entity divided by the volume (V) of the system containing the component. The fundamental unit is mol m-3 but practical units are mol dm-3 or mol L-1 (not molarity). Related term: absolute lethal concentration,?lethal concentration,maximum tolerable concentration, median ffectiveconcentration, median lethal concentration, median narcotic concentration, minimum lethal concentration, threshold concentration