Nuclear Physics And Radioactivity Question 256
Question: In a radioactive substance at $ t=0 $ , the number of atoms is $ 8\times 10^{4} $ . Its half life period is 3 years. The number of atoms $ 1\times 10^{4} $ will remain after interval [MP PMT/PET 1988]
Options:
A) 9 years
B) 8 years
C) 6 years
D) 24 years
Show Answer
Answer:
Correct Answer: A
Solution:
By formula $ N=N_{0}{{( \frac{1}{2} )}^{t/T}} $ or $ 10^{4}=8\times 10^{4}{{( \frac{1}{2} )}^{t/3}} $ or $ ( \frac{1}{8} )={{( \frac{1}{2} )}^{t/3}} $ or $ {{( \frac{1}{2} )}^{3}}={{( \frac{1}{2} )}^{t/3}}\Rightarrow 3=\frac{t}{3} $ Hence t = 9 years.
BETA
