Answer: 1.2 fm (femtometers).
- A 1.2 fm (femtometers)
- B 1.2 nm
- C 12 pm
- D 0.53 Angstrom
Correct answer: A. 1.2 fm (femtometers)
Explanation: R = R₀ A<sup>1/3</sup> where R₀ ≈ 1.2-1.3 femtometers = 1.2 × 10⁻¹⁵ m. Nuclear density is roughly constant.
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.