Modern Physics 3 Question 40
39. At a given instant there are undecayed radioactive nuclei in a sample. After the number of undecayed nuclei reduces to . Calculate
(a) mean life of the nuclei,
(b) the time in which the number of undecayed nuclei will further reduce to
Show Answer
Solution:
- (a) In
, number of nuclei has been reduced to half (25% to .
Therefore, its half-life is
Relation between half-life and mean life is
(b) From initial