What is the basic difference between a nuclear fission reaction and a nuclear fusion reaction?

• A. Nuclear fission releases less energy per reaction than nuclear fusion.
• B. Nuclear fission occurs only in stars, while nuclear fusion occurs only in nuclear reactors.
• C. Nuclear fusion produces radioactive waste, while nuclear fission does not.
• D. Nuclear fission involves splitting a heavy nucleus into smaller nuclei, while nuclear fusion involves combining light nuclei to form a heavier nucleus.

Answer: (D)

Verified step by step guidance

1. Understand that nuclear fission and nuclear fusion are two different types of nuclear reactions involving changes in atomic nuclei.
2. Nuclear fission is the process where a heavy nucleus splits into two or more smaller nuclei, often releasing neutrons and a large amount of energy.
3. Nuclear fusion is the process where two light nuclei combine to form a heavier nucleus, also releasing energy, typically more per reaction than fission.
4. Recognize that fission reactions are commonly used in nuclear reactors and produce radioactive waste, while fusion reactions power stars and currently have limited practical use on Earth.
5. Summarize the key difference: fission splits heavy nuclei, fusion combines light nuclei, which is the fundamental distinction between the two processes.