Physics – 5.2.3 Radioactive decay | e-Consult

Alpha Decay: An alpha particle (⁴He nucleus) is emitted. The atomic number (Z) of the parent nucleus decreases by 2, and the mass number (A) decreases by 4. For example, ²³⁸U -> ²³⁴Th + ⁴He.

Beta Decay: A beta particle (an electron or positron) and a neutrino are emitted. In beta-minus decay, a neutron in the nucleus converts into a proton, increasing the atomic number by 1 and leaving the mass number unchanged. In beta-plus decay, a proton converts into a neutron, decreasing the atomic number by 1 and leaving the mass number unchanged. For example, ¹⁴C -> ¹⁴N + e^- + ν_e (beta-minus).

Gamma Decay: Gamma radiation (high-energy photons) is emitted. This occurs when a nucleus is in an excited state after undergoing alpha or beta decay. The atomic number (Z) and mass number (A) of the parent nucleus remain unchanged. Gamma decay simply releases excess energy from the nucleus.