Question

The ratio of the rate of disintegration and the initial number of nuclei of a radioactive substance is $0.25~hour^{-1}$. The time taken (in hours) for the number of nuclei of this substance to become $\frac{1}{\sqrt{e}}$ times the initial number of nuclei is}

• A. 0.5
• B. 1
• C. $\sqrt{2}$
• D. 4

Hint:

Remember: \[ R=\lambda N \] and \[ N=N_0e^{-\lambda t} \] These two formulas solve most radioactive decay problems.

Answer 1

The Correct Option is D