How do radioactive fission products become more stable?

Fission fragments produced during nuclear fission are highly unstable because they possess an abnormally high ratio of neutrons to protons compared to stable nuclei. To achieve stability, these fragments undergo a series of radioactive decay processes known as a decay chain.123

The primary mechanism for reaching stability is beta decay, where a neutron within the nucleus is converted into a proton, accompanied by the emission of a beta particle (a negative electron) and an antineutrino. This process increases the atomic number (proton count) of the nucleus while keeping the mass number constant, effectively adjusting the neutron-to-proton ratio toward a more stable configuration.123

In addition to beta decay, these nuclei may emit neutrons or radiate energy through gamma decay to shed excess energy. This step-by-step transformation continues through successive radioactive species until the nucleus reaches a final, stable state.13