How much time will elapse before the activity of patient falls to ? — Nuclear Chemistry and Radioactivity Chemistry Question

💡 Solution & Explanation

The effective decay constant is the sum of biological and radioactive decay constants. Effective half-life $T_{eff} = \frac{T_b \cdot T_r}{T_b + T_r} = \frac{24 \cdot 8}{24 + 8} = 6 \text{ h}$. The activity falls to half its initial value ($32 \mu\text{Ci} \to 16 \mu\text{Ci}$) in exactly one effective half-life. Therefore, correct answer is C.