What is meant by nuclear fission reaction ? Write an example of it.

^{235}_{92}U+nslow neutron^{141}_{56}Ba+^{92}_{36}Kr+3n

Nuclear fission reaction is a process in which a heavy atomic nucleus (such as uranium-235 or plutonium-239) splits into two smaller nuclei of comparable mass, accompanied by the release of a large amount of energy and additional neutrons. This reaction is initiated when a neutron collides with a heavy nucleus, causing it to become unstable and split. The released neutrons can further induce fission in other nuclei, creating a chain reaction.

Example: When a slow neutron collides with a uranium-235 nucleus, it splits into barium-141, krypton-92, and three additional neutrons, releasing energy:

$${}_{}^{}{}_{92}^{235}\mathrm{U}+\mathrm{n}\to {}_{}^{}{}_{56}^{141}\mathrm{Ba}+{}_{}^{}{}_{36}^{92}\mathrm{Kr}+3\mathrm{n}+\text{energy}$$