Nuclear Chemistry Question 32
Question: What is the half-life of a radioactive substance if 87.5% of any given amount of the substance disintegrates in 40 minutes
[Kerala CET 1996]
Options:
A) 160 min
B) 10 min
C) 20 min
D) 13 min 20 sec
Show Answer
Answer:
Correct Answer: D
Solution:
$ K=\frac{2.303}{40}\log \frac{a}{a-0.875a}=\frac{2.303}{40}\log 8 $
$ =0.05199{{\min }^{-1}} $
$ {t _{1/2}} $ = 0.693/0.05199 = 13.33 min. = 13 min 20 sec.
BETA
