Answer: 5:3.
- A 3:5
- B 5:3
- C 25:9
- D 125:27
Correct answer: B. 5:3
Explanation: R ∝ A1/3, so R1/R2 = (125/27)1/3 = 5/3.
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.