The Atomic bomb!

For anyone who's interested:

Atomic bomb, also called atom bomb, weapon with great explosive power that results from the sudden release of energy upon the splitting, or fission, of the nuclei of such heavy elements as plutonium or uranium.

When a neutron strikes the nucleus of an atom of the isotopes uranium 235 or plutonium-239, it causes that nucleus to split into two fragments, each of which is a nucleus with about half the protons and neutrons of the original nucleus. In the process of splitting, a great amount of thermal energy, as well as gamma rays and two or more neutrons, is released. Under certain conditions, the escaping neutrons strike and thus fission more of the surrounding uranium nuclei, which then emit more neutrons that split still more nuclei. This series of rapidly multiplying fissions culminates in a chain reaction in which nearly all the fissionable material is consumed, in the process generating the explosion of what is known as an atomic bomb.