Atoms And Nuclei Question 365
Question: A 280 days old radioactive substance shows an activity of 6000 dps, 140 days later its activity becomes 3000 dps. What was its initial activity?
Options:
A) 20000 dps
B) 24000 dps
C) 12000 dps
D) 6000 dps
Show Answer
Answer:
Correct Answer: B
Solution:
- $ \lambda =\frac{2.303}{280}\log \frac{A_{0}}{6000}=\frac{2.303}{420}\log \frac{A_{0}}{3000} $ On solving, we get, $ {{A}_{0}}=24000dps. $
