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Specific activity (symbol a) is the activity per unit mass of a radionuclide and is a physical property of that radionuclide. [ 1 ] [ 2 ] It is usually given in units of becquerel per kilogram (Bq/kg), but another commonly used unit of specific activity is the curie per gram (Ci/g).
Neutron activation analysis is a sensitive multi-element analytical technique used for both qualitative and quantitative analysis of major, minor, trace and rare elements.. NAA was discovered in 1936 by Hevesy and Levi, who found that samples containing certain rare-earth elements became highly radioactive after exposure to a source of neutrons
Neutron activation is the process in which neutron radiation induces radioactivity in materials, and occurs when atomic nuclei capture free neutrons, becoming heavier and entering excited states. The excited nucleus decays immediately by emitting gamma rays , or particles such as beta particles , alpha particles , fission products , and ...
Not all molecules in the solution have a P-32 on the last (i.e., gamma) phosphate: the "specific activity" gives the radioactivity concentration and depends on the radionuclei's half-life. If every molecule were labelled, the maximum theoretical specific activity is obtained that for P-32 is 9131 Ci/mmol.
The following table shows radiation quantities in SI and non-SI units. W R (formerly 'Q' factor) is a factor that scales the biological effect for different types of radiation, relative to x-rays (e.g. 1 for beta radiation, 20 for alpha radiation, and a complicated function of energy for neutrons). In general, conversion between rates of ...
Liquid scintillation counting is the measurement of radioactive activity of a sample material which uses the technique of mixing the active material with a liquid scintillator (e.g. zinc sulfide), and counting the resultant photon emissions.
Radiochemistry is the chemistry of radioactive materials, where radioactive isotopes of elements are used to study the properties and chemical reactions of non-radioactive isotopes (often within radiochemistry the absence of radioactivity leads to a substance being described as being inactive as the isotopes are stable).
The activity of a sample decreases with time because of decay. The rules of radioactive decay may be used to convert activity to an actual number of atoms. They state that 1 Ci of radioactive atoms would follow the expression N (atoms) × λ (s −1) = 1 Ci = 3.7 × 10 10 Bq, and so N = 3.7 × 10 10 Bq / λ, where λ is the decay constant in s ...