Nuclear Physics And Radioactivity Question 315
Question: The half-life of $ ^{131}I $ is 8 days. Given a sample of $ ^{131}I $ at time t = 0, we can assert that [IIT 1998]
Options:
A) No nucleus will decay before t = 4 days
B) No nucleus will decay before t = 8 days
C) All nuclei will decay before t = 16 days
D) A given nucleus may decay at any time after t = 0
Show Answer
Answer:
Correct Answer: D
Solution:
Number of nuclei decreases exponentially $ N=N_{0}{{e}^{-\lambda t}} $ and Rate of decay $ ( -\frac{dN}{dt} )=\lambda N $ Therefore, decay process losts up to t = ¥. Therefore, a given nucleus may decay at any time after t = 0.
BETA
