Nuclear fission is a process 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 reaction typically occurs in heavy elements like Uranium or Plutonium, and it is the fundamental principle behind nuclear reactors and atomic bombs. During fission, the splitting of the nucleus releases neutrons, which can then trigger further fission reactions in nearby nuclei, leading to a chain reaction. This property is harnessed in nuclear power plants to generate electricity, making nuclear fission a crucial component of modern energy production.