The principal radioactive decay modes transform nuclei in different ways and are governed by different interactions.

In alpha decay, a heavy nucleus emits a helium-4 nucleus: $$^A_ZX\rightarrow {}^{A-4}_{Z-2}Y+{}^4_2\alpha.$$ The alpha particle escapes by quantum tunneling through the nuclear Coulomb barrier. The daughter has two fewer protons and two fewer neutrons.

In beta-minus decay, a neutron converts into a proton while emitting an electron and an electron antineutrino: $$n\rightarrow p+e^-+\bar\nu_e.$$ At the nuclear level, $$^A_ZX\rightarrow{}^A_{Z+1}Y+e^-+\bar\nu_e.$$ Beta-plus decay and electron capture convert a proton into a neutron through related weak-interaction processes. The neutrino is essential for conserving energy, momentum and angular momentum event by event.

In gamma decay, an excited nucleus emits a photon: $$X^*\rightarrow X+\gamma.$$ The proton and neutron numbers do not change; only the nuclear energy state changes.

The decay mode is constrained by energy availability and conservation laws. Alpha decay is common in heavy nuclei, beta processes move nuclei between neutron/proton compositions, and gamma emission often follows another reaction that leaves a nucleus excited. These modes are not simply three strengths of the same radiation: they involve different emitted particles and underlying interactions.