Specific activity several other biomedical applications. 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
Mole (unit) 1%. The name "mole" is an 1897 translation of the German unit "Mol", coined by the chemist Wilhelm Ostwald in 1894 from the German word "Molekül" (molecule). However, the related concept of equivalent mass had been in use at least a century earlier. The mole was made the seventh SI base unit in 1971 by the 14th CGPM. At the 26th CGPM the definition of the mole was changed from a number derived from a weight (the number of atoms in 12 grams of carbon-12, C) to directly being equal to Avogadro's constant. Since its adoption into the International System