system
Given the following post, respond as if you're commenting on Reddit:
human
Can you make a nuclear bomb with any element?

Could you use an element like gold, or sodium, instead of uranium?
gpt
No. There are a few basic requirements that a nuclear warhead should meet in order to be useful. First, you need nuclear reactions that release energy, and as much of it as possible. Second, you need this reaction to be as easy as possible to initiate; you don’t want a large energy barrier to overcome. In broad strokes, this already limits you to fission of very heavy nuclides, and fusion of very light nuclides. In the case of fission, you want to maximize the probability of each fission reaction occurring, so this further limits you to *fissile* fuel. Fissile nuclides are defined by the fact that they can fission in the presence of neutrons of arbitrarily low energies. In other words, there is no energy threshold for neutron-induced fission. This generally implies that the probability of a neutron causing the nucleus to fission is proportional to 1/sqrt(E), and it’s very large in magnitude compared to other cases. In the case of fusion, you want to minimize the energy barrier required for the reaction to occur. The Coulomb barrier is proportional to Z*_1_*Z*_2_*, where the Z’s are the atomic numbers of the target and projectile. So obviously the lowest Coulomb barrier will be for hydrogen on hydrogen reactions.

If you want to use fissile nuclides for a fission bomb, this limits you to a handful of heavy species. Engineering/practical constraints further limit you down to uranium-233, uranium-235, plutonium-239, and plutonium-241.

If you want to use hydrogen fusion for a thermonuclear weapon, you’re limited to deuterium and tritium.

For a sense of scale, the DD and DT fusion reactions used in thermonuclear weapons release about 10 MeV of energy per reaction, and neutron-induced fission of uranium-235 releases an average of 200 MeV per reaction (it’s an average because there are many possible exit channels).

So to summarize, *no*, you can’t just use whatever you want if you want your bomb to actually work, and satisfy a few basic requirements desirable for a weapon.