Splitting an atom, also known as nuclear fission, refers to the process of breaking apart the nucleus of an atom into smaller fragments. This process releases an enormous amount of energy. The energy released during nuclear fission is primarily a result of the conversion of mass into energy, as described by Einstein's famous equation, E=mc².
Nuclei of certain isotopes, such as uranium-235 and plutonium-239, can undergo nuclear fission when they absorb a neutron. When a nucleus undergoes fission, it splits into two or more smaller nuclei, called fission fragments, along with the release of several high-energy neutrons. These neutrons can go on to initiate a chain reaction by colliding with other atomic nuclei, causing them to undergo fission as well.
The fission process releases an enormous amount of energy because the total mass of the fission fragments is slightly less than the mass of the original nucleus. This "missing" mass is converted into energy according to Einstein's equation. The released energy is in the form of kinetic energy of the fission fragments, as well as the kinetic energy of the emitted neutrons.
This release of energy is what makes nuclear fission a potent source of power. It is utilized in nuclear reactors to generate electricity through controlled chain reactions. The energy released per fission event is millions of times greater than that of a chemical reaction, making nuclear fission a highly concentrated and efficient source of power.