Nuclear Physics And Radioactivity Question 362
Question: The half-life of a radioactive substance against a-decay is $ 1.2\times 10^{7}s $ . What is the decay rate for $ 4\times 10^{15} $ atoms of the substance [AMU (Med.) 2002]
Options:
A) $ 4.6\times 10^{12}atoms/s $
B) $ 2.3\times 10^{11}atoms/s $
C) $ 4.6\times 10^{10}atoms/s $
D) $ 2.3\times 10^{8} $
Show Answer
Answer:
Correct Answer: D
Solution:
$ \frac{dN}{dt}=-\lambda N\Rightarrow | \frac{dN}{dt} |=\frac{0.693}{{T_{1/2}}}\times N $ $ =\frac{0.693}{1.2\times 10^{7}}\times 4\times 10^{15}=2.3\times 10^{8}atoms/\sec $
BETA
