Question
The mean-life of a radioactive sample is Tm. What is the time in which 50% of this sample would get decayed?
Solution
The half-life period is,
T1/2 = 0.693 Tm
where, Tm is the mean half-life.
To decay by 50% of the sample one half-life is required.
Therefore, time taken is 0.693 Tm to decay by 50%.
