<human>:  Can you explain the process of nuclear fission?
<bot>: Nuclear fission is the process of splitting apart a larger atom into two or more smaller atoms and releasing a large amount of energy. This process is caused when a neutron is fired at a larger atom such as uranium or plutonium and that uranium or plutonium atom absorbs the neutron. This causes the nucleus to become unstable and split into two smaller atoms, along with one or two neutrons and releasing a large amount of energy in the form of gamma rays or heat. The process can also produce neutrons which can in turn cause other atoms to undergo the same process and release even more energy. This is what is responsible for the sustained chain reaction seen in nuclear power plants.