A) \[0.8\times {{10}^{10}}\]
B) \[2.1\times {{10}^{10}}\]
C) \[3.2\times {{10}^{10}}\]
D) \[0.3\times {{10}^{10}}\]
Correct Answer: A
Solution :
Number half-life \[n=\frac{12}{4}=3\] This fraction undecayed \[\frac{N}{{{N}_{0}}}={{\left( \frac{1}{2} \right)}^{3}}=\frac{1}{8}\] So, \[N=\frac{1}{8}{{N}_{0}}=\frac{1}{8}\times 6.4\times {{10}^{10}}\] \[=0.8\times {{10}^{10}}\]You need to login to perform this action.
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