Uranium is used in atomic weapons and in nuclear power plants because it is a radioactive element. The atoms of a radioactive element break down over a period of time, losing particles from their nucleus and releasing energy.
Normally, this breakdown happens in only a few uranium atoms at a time. But in an atomic bomb, the atoms break down very quickly, releasing great amounts of energy all at once.
Uranium atoms break down inside an atomic bomb because they’re hit with nuclear particles called neutrons. When a neutron strikes the nucleus of an uranium atom, it causes the nucleus to split apart.
This releases energy and sends particles from the uranium atom crashing into other atoms, which then split, sending out more energy and particles, and so on. This process is called a
chain reaction.
Once the chain reaction inside the atomic bomb’s uranium begins, it keeps going until most of the atoms have been split. This happens in a fraction of a second, so that all the uranium’s energy is released at once.
The breakdown of the atoms in just one pound of uranium can produce energy equal to the burning of almost three million pounds of coal!
