Question

If the half life of a radioactive sample is 10 hours, its mean life is.

• A. 14.4 hours
• B. 7.2 hours
• C. 20 hours
• D. 6.93 hours

Answer 1

Answer: (A)

14.4 hours

Answer 2

Mean life $= \frac{Half\mspace{6mu} life}{0.6931} = \frac{10}{0.6931} = 14.4\mspace{6mu} hours$