Question: Q. 9. (i) Derive the mathematical expression for the radioactive decay for a sample of a radioactive nucleus.
(ii) How is the mean life of a given radioactive nucleus related to the decay constant?
Show Answer
Solution:
Ans. (i) Let there be
If
or
(ii) The half life of ${ }{92}^{238} \mathrm{U}
R A [OD Comptt. I, II, III 2014]
(i) Try yourself, Similar to Q. 7, Short Answer Type Questions-II of this topic.
The S.I. unit of ‘activity’ is becquerel.
(ii) Try yourself, Similar to Q. 8, Short Answer Type Questions-II
Commonly Made Errors
- Few students don’t recall the correct formula.
- A number of students do calculation mistake/put wrong values in the formula.