For the radioactive material half life is 10 minutes. If initially there are 800 number of nuclei the time taken (in minutes) for the disintegration of 600 nuclei is
Answer & explanation
Correct answer: option 3
The correct answer is option (3) : 20 minutes
600 Nuclei have been disintegrated, hence number of nuclei left = 200
Now, $\left(\frac{N}{N_0}\right)=\left(\frac{1}{2}\right)^n⇒\left(\frac{200}{800}\right)^n=\left(\frac{1}{2}\right)^n⇒n=2$
Time take for disintegration $=2\times 10=20 minutes$