Nuclear fission definition

A nuclear fission can be defined as the artificial disintegration of an atom in a two unequal and un-identical atoms, or in other word we can define a nuclear fission as the splitting of a larger atomic nucleus into a smaller nuclei with the emission of either alpha, beta , gamma, neutron, etc.

 In nuclear fission larger nucleus called the target is shot by particles called projectiles, this particles can be deuterons, protons or neutrons. The larger nuclear then become unstable and splits into smaller stable atoms