Atoms And Nuclei Question 378
Question: One gram of a radioactive sample of half-life 10 min is sealed in a capsule at time t=0. Amount of sample decayed up to 5 min is
Options:
A) 0.293g
B) 0.5g
C) 0.25g
D) 0.707g
Show Answer
Answer:
Correct Answer: A
Solution:
-
Use the relation $ N=N_{0}{{e}^{-\lambda t}} $ where the decay constant
$ \lambda =(0.693/T_{half}). $ The half-life period
$ T_{half} $ is given to be 10min.
The amount N of radioactive sample remaining at the end of 5 min comes out to be about $ 0.707g, $
so that the amount of sample decayed is $ (1-0.707)=0.293g. $
