Specific activity Specific activity Specific activity is the activity per quantity of a radionuclide and is a physical property of that radionuclide. Activity is a quantity related to radioactivity. The SI unit of activity is the becquerel (Bq), equal to one reciprocal second. The becquerel is defined as the number of radioactive transformations per second that occur in a particular radioactive isotope. Its related non-SI unit equivalent is the Curie (Ci) which is transformations per second. Since the probability of radioactive decay for a given radionuclide is a fixed physical quantity (with some slight exceptions, see changing decay rates), the number of
Strontium unit to have three to four strontium units. The strontium unit was formerly known briefly as the sunshine unit, a term promoted by the United States Department of Defense until public ridicule brought about its disuse. (Among the sources of this outcry was a George Carlin performance, released on the CD "", during a passage on governmental euphemisms for dangerous or unethical activities: "The Pentagon actually measures nuclear radiation in something they call 'sunshine units'!") Strontium unit The strontium unit is a unit used to measure the amount of radioactivity from strontium-90, a radionuclide found in nuclear fallout, in a subject's