Which process involves splitting the nucleus of an atom into smaller nuclei?

The process of splitting the nucleus of an atom into smaller nuclei is known as nuclear fission. During fission, a heavy nucleus—typically that of uranium or plutonium—is bombarded with a neutron, which causes it to become unstable and break apart into two or more smaller nuclei, along with the release of a significant amount of energy. This process is fundamental in nuclear reactors and atomic bombs, where the energy released can be harnessed for various applications or, in the case of weapons, result in an explosive force.

Nuclear fusion, on the other hand, involves the merging of two light atomic nuclei to form a heavier nucleus, releasing energy in the process. This is the reaction that powers stars, including our sun.

Radioactive decay refers to the process by which unstable isotopes lose energy by emitting radiation, resulting in the transformation into more stable forms, which does not involve splitting the nucleus but rather changing it over time.

Chemical reactions involve the rearrangement of electrons in atoms to form new substances, and they do not alter the nuclei of the involved atoms. Thus, nuclear fission is specifically distinguished by its mechanism of splitting rather than merging, decaying, or merely rearranging electron configurations.