What happens during radioactive decay, and what is the result at the end of radioactive decay

Radioactive decay occurs when an atom has either to many or to few neutrons and becomes unstable and start to emit radio active radioactive radiation and the atom start to decompose.

At the end two things can happen either the atom will transform in a new element with a lower atomic # and atomic mass # or the remaining neutron will transform into an electron and be on its own way