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

The process that involves the splitting of the nucleus of an atom into smaller nuclei is known as fission. During fission, a heavy atomic nucleus, such as uranium-235 or plutonium-239, absorbs a neutron and becomes unstable, leading to its division into two or more smaller nuclei, along with the release of a significant amount of energy and additional neutrons. This can result in a chain reaction if the released neutrons go on to trigger further fission events in nearby nuclei, which is the fundamental principle behind nuclear reactors and atomic bombs.

In contrast, fusion is the process where two light atomic nuclei combine to form a single heavier nucleus, releasing energy in the process. Radiation refers to the emission of energy as electromagnetic waves, while decay typically refers to the process of radioactive decay, in which unstable isotopes lose energy by emitting radiation. Each of these processes is distinct and serves different purposes within the fields of nuclear physics and energy production.