"Activity of potassium-40 {40K CAS 13966-00-2} per unit wet weight of biota {Perca fluviatilis (ITIS: 168470: WoRMS 151353)}"@en . . "SDN:P01::APO07137" . "The rate of radioactive disintegrations due to the specified nuclide per unit weight of the specified organism or part thereof without drying."@en . .