Describe the difference between nuclear fission and nuclear fusion.

Nuclear fission is the process of splitting a large unstable nucleus into smaller nuclei, releasing energy and neutrons. In contrast, nuclear fusion involves the joining of two light nuclei to form a heavier nucleus, also releasing energy. Fission typically occurs in heavy elements like uranium, while fusion occurs in lighter elements like hydrogen.

This question assesses the ability to differentiate between two fundamental nuclear processes. A strong answer clearly outlines the mechanisms and examples of each process, demonstrating a solid grasp of nuclear physics concepts.