Nuclear Physics And Radioactivity Question 358
Question: 1 mg gold undergoes decay with 2.7 days half-life period, amount left after 8.1 days is [UPSEAT 2001]
Options:
A) 0.91 mg
B) 0.25 mg
C) 0.5 mg
D) 0.125 mg
Show Answer
Answer:
Correct Answer: D
Solution:
$ N=N_{0}{{( \frac{1}{2} )}^{n}}\Rightarrow N=N_{0}{{( \frac{1}{2} )}^{t/{T_{1/2}}}} $
$ \Rightarrow N=1\times {{( \frac{1}{2} )}^{\frac{8.1}{2.7}}}={{( \frac{1}{2} )}^{3}}=\frac{1}{8} $
$ \Rightarrow N=\frac{1}{8}mg=0.125\ mg $
BETA
