Which process releases energy by splitting a heavy nucleus into lighter nuclei?

Which process releases energy by splitting a heavy nucleus into lighter nuclei?

• A. Fusion
• B. Fission
• C. Radioactive decay
• D. Ionization

Answer: (B)

Splitting a heavy nucleus into lighter nuclei releases energy because of the way binding energy changes with mass. In fission, the original heavy nucleus has a certain mass that’s not fully accounted for by the binding energy of its many nucleons. When it splits into two (or more) lighter fragments, the resulting nuclei have a higher average binding energy per nucleon. The difference in binding energy shows up as released energy (via the mass defect: a tiny amount of mass converted to energy according to E=mc^2), mainly as kinetic energy of the fragments and some radiation. This is why heavy nuclei like uranium can release a lot of energy when they split. By contrast, fusion releases energy by combining light nuclei, radioactive decay involves spontaneous changes without splitting into lighter parts, and ionization removes electrons rather than altering the nucleus.

Splitting a heavy nucleus into lighter nuclei releases energy because of the way binding energy changes with mass. In fission, the original heavy nucleus has a certain mass that’s not fully accounted for by the binding energy of its many nucleons. When it splits into two (or more) lighter fragments, the resulting nuclei have a higher average binding energy per nucleon. The difference in binding energy shows up as released energy (via the mass defect: a tiny amount of mass converted to energy according to E=mc^2), mainly as kinetic energy of the fragments and some radiation.

This is why heavy nuclei like uranium can release a lot of energy when they split. By contrast, fusion releases energy by combining light nuclei, radioactive decay involves spontaneous changes without splitting into lighter parts, and ionization removes electrons rather than altering the nucleus.