Radioactive displacement law of Fajans and Soddy

The law of radioactive displacements, also known as Fajans's and Soddy's law, in radiochemistry and nuclear physics, is a rule governing the transmutation of elements during radioactive decay.

It is named after Frederick Soddy and Kazimierz Fajans, who independently arrived at it at about the same time in 1913.

[1][2] The law describes which chemical element and isotope is created during the particular type of radioactive decay:

Displacements resulting from various decay modes of a radionuclide . Horizontal axis: atomic number Z . Vertical axis: neutron number N