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 stationary nucleus of 7bl.mzb lz30e uranium-238hc3 us/ ltl cd9u6rr*i7 25ayy undergoes alpha decay to form thorium-234. The initial speed of the alpha particle is v. What is correct about cl9d7 csu rhyal2 *i5y/ utr63the magnitude of the thorium-234 velocity and its direction?
A. Magnitude is $\frac{4}{238}\,v$ ; Direction is Same as the alpha particle
B. Magnitude is $\frac{234}{238}\,v$ ; Direction is Opposite to the alpha particle
C. Magnitude is $\frac{234}{238}\,v$ ; Direction is Same as the alpha particle
D. Magnitude is $\frac{4}{238}\,v$ ; Direction is Opposite to the alpha particle
参考答案: D
本题详细解析:
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