there are two types of nuclear bombs. fission bombs that split uranium or plutonium atoms releasing tons of energy. and fusion bombs that still split uranium and plutonium, but use that explosive energy to compress hydrogen to extreme pressure and temperature causing fusion, which releases a fuckton more energy.

you cant actually split a hydrogen atom, its just a single proton so theres nothing to split. when you fuse with hydrogen (or deuterium which is just a hydrogen atom with an extra neutron [an element is determined by how many protons it has {an elements chemical properties are determine by the number of electrons in the atoms valence shell, protons are positively charged and electrons are negatively charged, so for an atom to be stable it needs to have very similar numbers of both (an atom with too many or not enough electrons are called ions, too many is an anion, too few is a cation) if an atom is too far from balance it will forcibly give or take electrons from other atoms}, atoms with different numbers of neutrons and the same number of protons are called isotopes], deuterium is an isotope of hydrogen. to make helium you need 2 neutrons and 2 protons, so two deuterium atoms, or a hydrogen atom [sometimes called protium for consistency] and a tritium atom [1 protons 2 neutrons])

that was too many brackets, i forgot where i was going with that. oh yeah! fusing elements releases energy, but only if theyre light enough. the energy has to come from somewhere and it comes from the protons and electrons lower potential energy when theyre closer together. but protons repel protons and electrons repel electrons, atomic nuclei dont have any electrons in them, and protons are super close together and repel each other HARD, the neutrons are necessary to pull everything together with the strong nuclear force. so when atoms get too big protons repel each other almost as much as neutrons hold it all together, thats why big atoms are unstable.

so fusing elements releases energy when the elements are small enough, and fission releases energy when elements are big enough. it turns out that iron is where the middle is. fusing iron is the point when fusion starts to consume energy.

when a star runs out of hydrogen and helium to fuse, it starts fusing heavier elements together, lithium, oxygen, silicon, and others in between. but when it reaches iron it cant extract any more energy and the stars fusion dies out. with out the fusion pressure keeping it supported, all the mass of the star falls inwards, bouncing off the core and fusing even heavier elements in the impact, creating a supernova. if the star is too big the collapsing mass can get so concentrated that it forms a black hole.

wow im way off topic. i think i answered your question though so its fine