What occurs during nuclear fission?

During nuclear fission, a heavy nucleus, such as that of uranium, absorbs a neutron, which leads to its instability. This instability causes the nucleus to split into two or more smaller nuclei, along with the release of a significant amount of energy and additional neutrons. The energy released during this process is due to the conversion of mass into energy, as described by Einstein's equation, E=mc². The released neutrons can further induce fission in nearby nuclei, potentially resulting in a chain reaction, which is a fundamental principle behind the operation of nuclear reactors and atomic bombs.

The choice indicating the absorption of a neutron by a uranium atom leading to its splitting and energy release accurately describes the process and consequences of nuclear fission.