Which term describes energy from nuclear fission and fusion?

• A. Mechanical Energy
• B. Thermonuclear Energy
• C. Photoelectric Energy
• D. Electromagnetic Energy

Answer: (B)

Energy released from changes in the nucleus during fission or fusion is described as thermonuclear energy. When a heavy nucleus splits or light nuclei fuse, some mass is converted to energy according to E=mc^2, and this energy usually appears as heat and kinetic energy in the reacting system. The term thermonuclear emphasizes the extremely high temperatures involved in these nuclear reactions, especially fusion, and it is used to describe the energy released in such processes. The other terms don’t fit because mechanical energy is about motion or position, the photoelectric term relates to electrons being ejected by light, and electromagnetic energy refers to energy carried by electromagnetic waves rather than energy from changes in the nucleus.