What kinds of radiation can a radioactive isotope emit?

Radioactive isotopes emit various forms of radiation as they undergo spontaneous decay to reach a more stable state. The most common emissions include:12

• Alpha particles ($\alpha$): These are nuclei of helium-4 atoms, consisting of two protons and two neutrons. They are relatively heavy and carry a positive charge.123
• Beta particles ($\beta$): These consist of high-speed electrons (beta-minus, $e^{-}$) or positrons (beta-plus, $e^{+}$), which are the antiparticles of electrons.14
• Gamma rays ($\gamma$): These are high-energy, short-wavelength electromagnetic radiation (photons) emitted when a nucleus transitions from a higher to a lower energy state.526
• Neutrinos and antineutrinos: These are neutral particles with very little mass that are frequently produced during beta decay.14

In less common forms of radioactive decay, isotopes may also emit neutrons, protons, or fission fragments, which are complex nuclei resulting from the splitting of a parent nucleus. Additionally, processes such as internal conversion and internal pair production can occur during gamma decay, resulting in the emission of electrons or electron-positron pairs.165