An atomic bomb works because of something called radioactive decay. Atoms (a really really small bit of matter) are made of three kinds of things: neutrons, electrons and protons. Generally, the number of protons and electrons will determine how the atom behaves. They’re why hydrogen and oxygen will burn and make water.

In an atom, the protons are all jammed in the middle, with electrons going super duper fast around them. Because of their charge, protons don’t like to hang out together. Think of trying to push two magnets together; if you line them up right, the magnets will push away from each other; protons work kind of like that. They’re not super happy with all being clumped in the middle of the atom.

Special types of plutonium and uranium (which are kinds of metal)