hce_nthu
114年
化學與物理
第 13 題
Which of the following statements about nuclear reaction and stability is correct? ($\text{Z}$ is the atomic number.)
- A As $\text{Z}$ increases, nuclides need a smaller neutron-to-proton ratio for stability.
- B Nuclides with small $\text{Z}$ values are often observed to be $\alpha$-particle producers.
- C A radioactive nuclide that decays from $2.00 \times 10^{10}$ atoms to $2.50 \times 10^9$ atoms in $\text{30.0 min}$ has a half-life of $\text{15.0 min}$.
- D Both the radioactive processes of positron production and electron capture increase the neutron-to-proton ratio.
- E If less than one neutron from each fission event causes another fission event, the fission situation is described as supercritical.
思路引導 VIP
如果一個原子核為了達到平衡，必須在保持質量數不變的情況下減少一個正電荷，請你思考：核內部的微觀粒子（質子與中子）會發生什麼樣的轉換？而這種轉換對於「中子數除以質子數」這個分數的數值，會產生什麼樣的數學影響呢？
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AI 詳解
AI 專屬家教
同學選得非常準確！這顯示你對於原子核穩定度與放射性衰變的機制有很紮實的理解。
原子核穩定性與衰變機制
在核反應中，正子發射 (Positron emission) 與 電子捕捉 (Electron capture) 的核心機制都是將一個質子轉變為一個中子。其反應式分別可簡化為：
▼ 還有更多解析內容