NEET Solved Paper 2018 Question 13
Question: For a radioactive material, half-life is 10 minutes. If initially there are 600 number of nuclei, the time taken (in minutes) for the disintegration of 450 nuclei is [NEET - 2018]
Options:
A) 30
B) 10
C) 20
D) 15
Show Answer
Answer:
Correct Answer: C
Solution:
Number of nuclei remaining $ =600450=150 $ $ \frac{N}{{N_0}}={{( \frac{1}{2} )}^{n}} $ $ \frac{150}{600}={{( \frac{1}{2} )}^{\frac{t}{{{t} _{1/2}}}}} $ $ {{( \frac{1}{2} )}^{2}}={{( \frac{1}{2} )}^{\frac{t}{{{t} _{1/2}}}}} $
$ t=2{{t} _{1/2}}=2\times 10 $ =20 minute
