Geochronology and radiogenic tracers / Геохронология и радиогенные индикаторы

We have seen that radioactivity is not dependent on the chemical bonding of atoms, nor on temperature, nor on pressure. Radioactivity can be described as an event whose probability of occurrence is independent of time and depends only on the duration of measurement. The probability that a radioactive nuclide will decay per unit of time is noted λ. This probability, termed the decay constant, is specific to the radioactive nuclide under consideration. Radioactive decay, like incoming calls at a telephone exchange, is a prime example of a Poisson process, in which the number of events is proportional to the time over which the observation is made. In the absence of any other loss or gain, the proportion of parent atoms (or radioactive nuclides) disappearing per unit of time t is constant <...>