Nuclear fission is a process in which a heavy nucleus, such as uranium-235, undergoes a splitting reaction, resulting in two smaller nuclei. This reaction is initiated when the heavy nucleus is bombarded with a neutron.

During nuclear fission, the nucleus splits into two smaller nuclei and releases a significant amount of energy. This energy is emitted in the form of kinetic energy from the two smaller nuclei, as well as in the form of gamma rays and other subatomic particles.

The energy released from nuclear fission can be effectively harnessed to generate electricity in nuclear power plants. In these facilities, the rate of fission reactions is carefully controlled using control rods, which absorb excess neutrons to prevent the reactor from overheating. The heat produced by the fission reactions is then used to generate steam, which drives turbines to produce electricity.

While nuclear fission can occur spontaneously in certain isotopes, such as uranium-238, the frequency of spontaneous fission is notably low. In the context of nuclear weapons, fission reactions are utilized to create a chain reaction. In this scenario, each fission event releases additional neutrons, resulting in a rapid, uncontrolled release of energy that leads to a nuclear explosion.

In summary, nuclear fission is a powerful phenomenon that can be utilized for beneficial applications, such as electricity generation, yet it also possesses the potential for destructive use in nuclear weaponry.