Answer: 2×.
- A 2×
- B 4×
- C 8×
- D unchanged
Correct answer: A. 2×
Explanation: R ∝ A<sup>1/3</sup>, so 8<sup>1/3</sup> = 2; the radius doubles.
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.