Question

Mean life of a radioactive sample is 100 seconds. Then its half-life (in minutes) is-

• A. 0.693
• B. 1
• C. 10^–4
• D. 1.155

Answer 1

Answer: (D)

1.155

Answer 2

T_1/2 = 0.693 T_m = 0.693 × 100 = 69.3 sec

= $\frac { 69.3 } { 60 }$ min = 1.155 min