What is the total time in years required for a radioactive nuclide to decay to exactly th of its ini — Nuclear Chemistry and Radioactivity Chemistry Question

💡 Solution & Explanation

The activity of a radioactive substance drops to $(1/2)^n$ of its initial value after $n$ half-lives. We are given the remaining fraction is $1/8$, which is $(1/2)^3$. Thus, $n = 3$ half-lives have passed. Since each half-life is $10\text{ years}$, the total time taken is $3 \times 10 = 30\text{ years}$.