Environmental radioactivity g) to that of the soil water (Bq ml). If the radioactivity is tightly bonded to by the minerals in the soil then less radioactivity can be absorbed by crops and grass growing in the soil. One dramatic source of man-made radioactivity is a nuclear weapons test. The glassy trinitite formed by the first atom bomb contains radioisotopes formed by neutron activation and nuclear fission. In addition some natural radioisotopes are present. A recent paper reports the levels of long-lived radioisotopes in the trinitite. The trinitite was formed from feldspar and quartz which were melted by the heat. Two samples
Specific activity the radionuclide is given by where "m" is mass number of the radionuclide and "N" is the Avogadro constant. Specific radioactivity "a" is defined as radioactivity per unit mass of the radionuclide: In addition, decay constant "λ" is related to the half-life "T" by the following equation: Thus, specific radioactivity can also be described by This equation is simplified by When the unit of half-life converts a year For example, specific radioactivity of radium-226 with a half-life of 1600 years is obtained by This value derived from radium 226 was defined as unit of radioactivity known as Curie (Ci). Experimentally