Physics Unit30: Nuclear Physics and Radioactivity (id: 79c794728)

[单选题]
When an alpha particle i+-9/moe kqi xhs emitted from an unstable nucleus, the a.:rb3oc75vy zx - linbtomic number of the nucle3ob :iz-lrcxv. b 75nyus

A. increases by 2.
B. decreases by 2.
C. increases by 4.
D. decreases by 4.


参考答案:  B


本题详细解析: 暂无