Answer: Is strongest at short range inside nucleus.
- A Acts over long range in typical laboratory settings
- B Is repulsive between protons under usual circumstances
- C Is strongest at short range inside nucleus
- D Is weaker than gravity according to most researchers
Correct answer: C. Is strongest at short range inside nucleus
Explanation: Strong nuclear force: very short range (~1-3 fm), strongest known force, attractive: binds protons and neutrons in nucleus.
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.