Answer: neutron.
- A electron
- B positron
- C neutron
- D photon
Correct answer: C. neutron
Explanation: The neutron is electrically neutral and has a mass very slightly greater than that of the proton.
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.