Answer: Activity per unit mass.
- A Number of nuclei
- B Activity per unit mass
- C Total energy released
- D Half-life per gram
Correct answer: B. Activity per unit mass
Explanation: Specific activity = activity per unit mass (Bq/kg or Ci/g). Useful for comparing radioactivity of different materials.
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.