One of the hazards of nuclear explosion is the generation of and its subsequent incorporation in bon — Nuclear Chemistry and Radioactivity Chemistry Question

💡 Solution & Explanation

The half-life is $t_{1/2} = 2.81 \text{ years}$ and the total time is $t = 28.1 \text{ years}$. The number of half-lives is $n = t / t_{1/2} = 28.1 / 2.81 = 10$. The initial amount is $N_0 = 2.048 \text{ mg} = 2048 \text{ \mu g}$. The remaining amount $N$ after 10 half-lives is $N = N_0 / (2^n) = 2048 / (2^{10}) = 2048 / 1024 = 2 \text{ \mu g}$. Therefore, correct answer is 2.