Question: What is the primary process that occurs in nuclear fission?

Options:

1. The splitting of a heavy nucleus into lighter nuclei.
2. The fusion of light nuclei to form a heavier nucleus.
3. The emission of electrons from a nucleus.
4. The absorption of photons by a nucleus.

Correct Answer: The splitting of a heavy nucleus into lighter nuclei.

Solution:

Nuclear fission is the process in which a heavy nucleus splits into two or more lighter nuclei, accompanied by the release of energy.