Alpha, Beta and Gamma Radiations

An alpha particle is a helium-4 nucleus: **⁴₂He It contains: * 2 protons; * 2 neutrons; * charge `+2e`. In alpha decay: A → A−4 Z → Z−2 General form: ᴬZX → ᴬ⁻⁴Z₋₂Y + ⁴₂He**

In beta-minus decay, a neutron in the nucleus transforms into a proton while an electron and an antineutrino are emitted: **n → p + e⁻ + ν̄ₑ At nuclear-number level: A remains unchanged Z increases by 1**

Gamma radiation consists of high-energy photons emitted when a nucleus changes from an excited state to a lower-energy state. For gamma emission: **A unchanged Z unchanged**

Alpha: positively charged; relatively strongly ionizing; comparatively low penetration. Beta: charged; intermediate penetration/ionization. Gamma: uncharged photons; relatively high penetration; comparatively lower ionization per path length.

Alpha: **ΔA=−4, ΔZ=−2 Beta-minus: ΔA=0, ΔZ=+1 Gamma: ΔA=0, ΔZ=0**