Read the Assertion and Reason below and choose the correct option. — Nuclear Chemistry and Radioactivity Chemistry Question

💡 Solution & Explanation

The half-life is $t_{1/2} = \frac{\ln 2}{\lambda} \approx \frac{0.693}{\lambda}$, and the mean life is $\tau = \frac{1}{\lambda}$. Their ratio $\frac{t_{1/2}}{\tau} \approx 0.693$ is constant for all radionuclides. Thus, both statements are true and II is the correct explanation of I. Therefore, correct answer is A.