Question

In one average-life,

• A. half the active nuclei decay
• B. less than half the active nuclei today
• C. more than half the active nuclei decay
• D. all the nuclei decay

Answer 1

The correct option is C

more than half the active nuclei decay

We know that, $T_{1/2}=\tau ln\left(2\right)=0.693\tau$
So, in one average life, more than half the active nuclei decay.