1 g sample of `""^(152)`Sm has 27% purity and emits `alpha` - particles with half-life `10^(12)` year. Calculate the number of `alpha`-particles approximately emitted in 1 sec :

Options

A. 24
B. 48
C. 16
D. 32

Answer

A

Explanation

decay constant `lambda = (0.693)/(10^(12) xx 365 xx 24 xx 60 xx 60) = 2.2 xx 10^(-20) s^(-1)`
rate of `alpha` emission ` = lambda xx N = 2.2 xx 10^(-20) xx (1xx 27 xx 6.02 xx 10^(23))/(100 xx 152) = 24 alpha s^(-1)`