Question: What is nuclear fission?

Options:

1. The splitting of a heavy nucleus into lighter nuclei.
2. The combining of light nuclei to form a heavier nucleus.
3. The decay of a radioactive isotope.
4. The emission of radiation from 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, releasing a significant amount of energy in the process.