Question

what is nuclear fission​

Answer 1

A nuclear reaction in which a heavy nucleus splits spontaneously or on impact with another particle, with the release of energy.

Answer 2

NUCLEAR FISSION :

The process of splitting up of a fissile nucleus (like uranium, plutonium) by a slow moving neutron is called nuclear fission.

Nuclear Fission forms chain reaction so it is also called nuclear chain reaction.

It is a controlled reaction.

When a slow moving neutron strikes the U-235 nucleus, the following nuclear reactions takes place.

$\boxed{\sf{ {U}^{235}_{92} \: + {n}^{1} _{0} \longrightarrow \: {Ba}^{140} _{56}+ {Kr}^{93} _{36}+ {3}^{1} _{0}n + energy}}$

It can be observed that U-235 splits into

a) A heavy nucleus with mass number 140.

b) A light nucleus with mass number 93.

c) Three neutrons.

Nuclear Reactor :

A device in which electricity is produced by the process of controlled nuclear fission reaction is called nuclear reactor.