What characterizes both nuclear fission and fusion?

Both nuclear fission and fusion are characterized by their ability to release a significant amount of energy. In nuclear fission, heavy atomic nuclei, such as uranium or plutonium, are split into smaller nuclei along with the release of energy. This process is harnessed in nuclear power plants and atomic bombs. Conversely, nuclear fusion involves the combining of light atomic nuclei, like hydrogen isotopes, to form a heavier nucleus, which also releases a tremendous amount of energy as seen in stars, including our sun. The energy release from fusion is significantly greater than that from fission, making it a powerful source of energy.

While fission involves the breaking apart of atomic nuclei, fusion is based on the merging of nuclei. Additionally, both processes do not occur at normal temperatures; fission can occur at a range of temperatures, but fusion typically requires extreme temperatures and pressures to overcome the repulsive forces between positively charged nuclei. Lastly, neither fission nor fusion requires a chemical catalyst; they are nuclear reactions that proceed under specific conditions unrelated to chemical reactions. Thus, the defining characteristic of both processes is indeed the significant energy release.