Nuclear Chemistry Question 8
Question: A radioactive element with half-life 6.5 hrs has $ 48\times 10^{19} $ atoms. Number of atoms left after 26 hrs
[BHU 2003]
Options:
A) $ 24\times 10^{19} $
B) $ 12\times 10^{19} $
C) $ 3\times 10^{19} $
D) $ 6\times 10^{19} $
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Answer:
Correct Answer: C
Solution:
$ N _{t}=N _{o}{{( \frac{1}{2} )}^{n}} $
$ =48\times 10^{19}{{( \frac{1}{2} )}^{26/6.5}} $
$ =48\times 10^{19}{{( \frac{1}{2} )}^{4}}=3\times 10^{19} $ .
BETA
