Eli5: What exactly are the conditions that have to be met for a nuclear reaction to occur? Why does it have to involve Uranium 235 and similar isotopes? The world is made out of atoms. If we were to split the nuclei of the atoms of like a T shirt would it cause a nuclear reaction?

Question

Eli5: What exactly are the conditions that have to be met for a nuclear reaction to occur? Why does it have to involve Uranium 235 and similar isotopes? The world is made out of atoms. If we were to split the nuclei of the atoms of like a T shirt would it cause a nuclear reaction?

In: 6

Answer 1

A T-shirt is mostly light atoms like carbon and hydrogen, which take more energy to split than they release. They can however be fused to release energy, but it’s stupidly difficult to make it happen, normally only happening in the cores of stars.

U-235 releases energy when split, but crucially, also releases neutrons that can hit other atoms causing those to split too.