Where nuclear fission is found?

Answer 1

In a nuclear power plant and in nature in (low levels.)

With any form of radioactive decay it is possible for atoms to be split. The sustained reaction is the foundation of both nuclear weapons and nuclear power plants where the fission is self-sustaining for a period of time.

A simple physical model is a pool (billard) table when you initally break. The cue ball is a small particle that breaks up the racked balls. Now imagine hundreds if not millions of other racked balls. A chain reaction of breaks continues until there isn't enough energy to stustain the fission of atoms. Low levels of this happen all the time with radioactive material in nature. Once there is a "critical mass" of very specific radioactive material a sustained chain reaction happens. Controlled you can get nuclear power by siphoning the reaction in the form of heat to turn turbines for power, let it all go at once and you get a nuclear bomb.

Fission is the splitting of atoms, fusion is merging atoms. A hydrogen bomb uses both fission and fusion. Fission to start the reaction (Plutonium) and an outer shell that (Cesium,cobalt, if memory serves me correctly were two material used for the outer casing), from the force of the fission, causes the fusion of hyrodgen (hence H-Bomb).

Answer 2

Inside stars and research labs.