Answer is: nuclear change.
Transmutation is a process that involves a change in the nucleus of an atom. It can be natural or artificial.
For example: 14/7 N + 4/2 He --> 17/8 O + 1/1 H.
This example is the first artificial nuclear transmutation described by Rutherford in 1919.
Artificial transmutation can be expressed by nuclear reaction:
Target Nuclide + Bombardment Particle → New Nuclide + Ejected Particle.
