If the decay or disintegration constant of a radioactive substance is λ, then its half-life and mean life are respectively:
Correct answer: B. loge2/λ and τ = 1/λ
- A. 1/λ and loge2/λ
- B. loge2/λ and τ = 1/λ
- C. λloge2 and 1/λ
- D. λ/loge2 and 1/λ
Explanation
The half-life of a radioactive substance is the time it takes for the number of radioactive atoms to decrease to half of its original value. The mean life of a radioactive substance is the average time that a radioactive atom will exist before it decays. The half-life is given by T½ = loge2/λ, where λ is the decay constant. The mean life is given by τ = 1/λ.
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