Nuclear fission is a nuclear reaction in which the nucleus of an atom splits into two or more smaller nuclei, along with the release of a significant amount of energy. This process typically occurs in heavy elements such as uranium-235 or plutonium-239. The fission process can be initiated by the absorption of a neutron by the nucleus of the fissile atom. When the nucleus absorbs the neutron, it becomes unstable and splits into two smaller nuclei, known as fission fragments.
