Nuclear fission is the process in which a large nucleus splits into two smaller nuclei with the release of energy. In other words, fission the process in which a nucleus is divided into two or more fragments, and neutrons and energy are released.
The mass changes and associated energy changes in nuclear reactions are significant. For example, the energy released from the nuclear reaction of 1 kg of uranium is equivalent to the energy released during the combustion of about four billion kilograms of coal.
Continuous research or artificial transmutation and especially the study of induced radioactivity culminated in the discovery of nuclear fission which is accompanied by the release of enormous amounts of energy. In ordinary nuclear disintegrations, both natural and artificial, the nucleus is only chipped off rather than broken and accordingly, the amount of energy released is comparatively less i.e. from about 10 to 23 MeV. It was discovered in 1939 that the heavy unstable uranium nucleus when bombarded by neutrons splits into two almost equal fragments which fly apart with great speed and the amount of energy released per fission is about 200 MeV.
This division of a nucleus into two approximately equal parts as called nuclear fission.
