A parent nuclide (MP), after the emission of a particle, converts to a daughter nuclide (M'D), and the process is called disintegration. The rate of disintegration or is called radioactivity, and it is measured in disintegration per second (dps) or becquerel (1 Bq = 1 dps).
In all radioactive decay processes, the charge and the number of nucleons (proton and neutrons) are the same before and after the decay. This is the principles of conservation of charge and number of nucleons.
Regarding radioactive decay, the following aspects will be covered.