eli5: How does an H bomb work?


How does simply splitting one atom expel so much energy? There’s no way that much energy could fit into a hydrogen atom. There’s only one electron, which has the energy. How does one atom make a big explosion?

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Hydrogen bombs do not split an atom. They are actually creating a helium atoms through the fusion of two hydrogen atoms. And because the helium molecule has less binding energy than the hydrogen atoms, there’s a release of energy when the reaction happens

Very little energy in one atom.

But bombs are more than one atom. They’re lots of atoms in a chain reaction.

Fission bombs split atoms. Many atoms. H-bombs get their energy from the opposite process, fusing atoms. Again, though, fusing *lots* of atoms.

A regular bomb works off of a lot of explosive. Nukes are the same idea, but the explosive has a lot more energy per atom.

H-bombs work by joining atoms together, not by splitting them.

Imagine you have a bunch of magnets arranged on a table. Give them the right kind of nudge, and suddenly they all stick together, and give a lot of energy off in the form of sound (and heat, which we can’t see directly without the right equipment)

If you want to pull the magnets apart, you have to spend energy to do so.

If you had a *lot* of magnets, you’d get a lot of energy. I suppose one day a YouTuber will make a video “I arranged 1 million magnets and nudged them!” which will be fun to watch.

A bunch of hydrogen atoms might not look like it has a lot of energy, but nor did the magnets arranged on the table. Given the right kind of nudge though (unbelievably high pressure, and multi-million degree temperatures), the Hydrogen atoms join together to form larger atoms, and give off a lot of energy.

(Unlike magnets, there are limits to this: if the atoms get big enough, it costs energy to merge them, and we can get energy by splitting them)

An H-bomb is a fusion weapon. Atoms are combined to make bigger atoms

This is as opposed to a fission bomb, which works by splitting very large atoms into smaller atoms.

The part that is probably really confusing about this is that every fusion bomb also has a fission bomb built into it.

The only place we know of where fusion occurs naturally is at the center of a star where the high temperatures and pressures needed for fusion to occur are present.

The only way we know of to reproduce those conditions outside of a star is the brief moment of time after a fission bomb explodes.

So to create a fusion bomb, you take a fission bomb and pack the fusion bomb material right next to it, such that right after the fission reaction goes off, the conditions will be just right to kick off the fusion reaction in the fusion part of the bomb.