本题目来源于试卷: Nuclear & Quantum Physics E.3 Radioactive Decay，类别为 IB物理学
[单选题]
A pure radioactive sample of mass m has a decay constro1wspa8;-:qe q3:eazttha6v8tc 2 sant of λ. Its activity isuorav66ie48zs h+sp2 8zw2 ys given by A. Anots8h vi2u srz + ay6pw2ez68so4her pure sample of the same material has a mass 2m. Consider the following statements about the sample of mass 2m after an interval of two half lives.
I. The decay constant is $\frac{λ}{2}$.
II. The activity is $\frac{A}{2}$.
III. The mass of decayed nucleons in the sample is $\frac{m}{2}$.
Which of the statements is/are correct?
A. $I$ only
B. $II$ only
C. $III$ only
D. $II$ and $III$ only
参考答案: B
本题详细解析:
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