What is nuclear fission?

Nuclear fission is defined as the process where an atomic nucleus splits into two or more smaller nuclei, along with the release of a significant amount of energy and neutrons. This splitting occurs when a heavy nucleus, such as uranium-235 or plutonium-239, absorbs a neutron and becomes unstable, leading to its division. The neutrons released can then initiate further fission reactions, making it a critical process in nuclear reactors and atomic bombs.

Understanding nuclear fission as the splitting of an atom's nucleus captures both the essence of the process and its significance in nuclear physics and energy production. This definition highlights the core mechanism that drives the chain reactions vital for energy generation in nuclear power plants, or for the destructive power seen in nuclear weapons.