Fission fragments are what type of nuclei?

• A. Two or three lighter radioactive nuclei (fission products).
• B. Heavier stable nuclei are produced.
• C. Neutrinos are produced instead.
• D. Only protons are produced.

Answer: (A)

Fission fragments are the two (often two) lighter nuclei produced when a heavy nucleus fissions. These pieces are called fission products and are typically radioactive, decaying toward stability after the split. The heavy nucleus splits into lighter partners that carry away part of the original mass energy, and the remaining energy appears as kinetic energy of the fragments and as prompt neutrons. It’s not heavier stable nuclei that result, and the fragments are not neutrinos or only protons—each fragment is a full nucleus with both protons and neutrons.