The half life of `.^(215)At` is `100mu s`. The time taken for the radioacticity of `.^(215)At` to decay to `1//16^(th)` of its initial value is:
A. `400mu s`
B. `6.3mu s`
C. `40mu s`
D. `300mu s`
A. `400mu s`
B. `6.3mu s`
C. `40mu s`
D. `300mu s`
Correct Answer – `(a)`
`(1)/(16) = (1)/(2^(4)), :. n = 4, t_(1//2) = 100 mu s`
`:. T = t_(1//2) xx n`
`= 100xx4 = 400 mu s`