In the given diagram, the reaction is a graphical representation of the nuclear fission of one nucleus of Uranium 235 into two nuclei of Kr with three neutrons that leads to a chain reaction and releases a huge amount of energy and grow out of control.
With every fission, there are two neutrons emitted which results in splitting more nucleus into two nuclei and keep on growing and never die out. The amount of energy also keeps on growing with an increase in the reactions and fission. This reaction is used to generate electricity and nuclear weapons.
