Radioactive decay — Describe

Describe the effect of alpha decay, beta decay and gamma emission on the nucleus.

Alpha decay: the nucleus loses 2 protons and 2 neutrons, so the nucleon number decreases by 4 and the proton number decreases by 2, giving a more stable nucleus. Beta decay: a neutron in the nucleus changes into a proton and an electron (neutron -> proton + electron); the electron is emitted as the beta particle. This means the nucleon number is unchanged but the proton number increases by 1, which reduces the number of excess neutrons and increases stability. Gamma emission: the nucleus (often left in an excited, higher-energy state after alpha or beta decay) emits gamma radiation to lose excess energy; there is no change in proton number or nucleon number, but the nucleus becomes more stable. Overall, all three processes move an unstable nucleus towards a more stable arrangement of protons and neutrons.