Answer: 8.
- A 6
- B 10
- C 8
- D 4
Correct answer: C. 8
Explanation: Each alpha reduces A by 4. Change in mass number = 238 − 206 = 32, so 32/4 = 8 alpha particles are emitted.
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.