Radioactive displacement law of Fajans and Soddy

The Fajans soddyschen displacement laws (also radioactive laws of displacement ) are established by Kasimir Fajans 1913 and Frederick Soddy rules that describe how the order and mass number changes during radioactive decay. Your explanation found the rules later with the study of the structure of atomic nuclei and the nature of the " decay " processes (more precisely, conversion processes).

• When alpha decay a nuclide with a lower atomic number by two units created as the parent nuclide. The mass number decreases by four units here.
• In beta decay a nuclide produced the same mass number. The atomic number increases ( β - decay) or decreases ( β decay and electron capture ) by one unit.