Answer: Beta minus particle (electron).
- A An alpha particle, which would instead reduce the mass number by four
- B A gamma ray photon with no accompanying particle emission
- C Beta minus particle (electron)
- D A free proton ejected directly from the nucleus
Correct answer: C. Beta minus particle (electron)
Explanation: C-14 decay: ¹⁴₆C → ¹⁴₇N + β⁻ + antineutrino. Used for dating organic matter (half-life 5730 years).
Binding energy per nucleon rises sharply for light nuclei, peaks around iron-56 (the most stable nucleus), then slowly declines for heavier nuclei - which is exactly why fusing light nuclei or splitting heavy nuclei both release energy: each moves the products toward this stability peak.
Concept context
Radioactivity, nuclear reactions, fission, fusion, and binding energy.