Nuclear Physics And Radioactivity Question 67
Question: The half-life of radioactive Polonium (Po) is 138.6 days. For ten lakh Polonium atoms, the number of disintegrations in 24 hours is [Roorkee 1999]
Options:
A) 2000
B) 3000
C) 4000
D) 5000
Show Answer
Answer:
Correct Answer: D
Solution:
$ n=\frac{24}{24\times 138.6}=\frac{1}{138.6}; $ Now $ \frac{N}{N_{0}}={{( \frac{1}{2} )}^{n}}={{( \frac{1}{2} )}^{1/138.6}} $
$ \Rightarrow N=10,00000{{( \frac{1}{2} )}^{1/138.6}}=995011 $ So number of disintegration $ =1000000-995011=4989\approx 5000 $ .
BETA
