. _:b19810 _:b19811 . _:b19810 . _:b19799 . . . "Activity is the decay rate of a radioactive substance. It is a derived quantity in the International System of Units. Activity is 1 divided by time."@en . . . . . "activiteit"@nl . . . . . "activity"@en . _:b19810 . . _:b19799 . . _:b19811 . . . _:b19810 . . _:b19799 . "activity of a radionuclide"@en . _:b19799 . . . _:b19811 . _:b19811 . . . "activity (of a radionuclide)"@en . . "A" .