Which of the following best describes fission products?

• A. Gases released during chemical reactions
• B. Activation of corrosion products
• C. Non-radioactive byproducts
• D. Radioactive fragments left after a fission event

Answer: (D)

When a heavy nucleus undergoes fission, it splits into two lighter nuclei (fission fragments) and a few neutrons. Those lighter nuclei are typically radioactive because their neutron-to-proton balance isn’t in a stable range, so they decay by emitting radiation over time. That makes fission products the radioactive fragments left after a fission event.

Options about gases released during chemical reactions or about activation of corrosion products describe different phenomena, not the specific products of fission itself. Non-radioactive byproducts would be incorrect because the fragments produced by fission are usually radioactive.

So the best description is that fission products are radioactive fragments left after a fission event.