The half life of `""_(92)^(238)U`against `alpha` - decay is `13.86xx10^(16)` s . The activity of 1 g sample of is

Options

A. `1.26xx10^(4)s^(-1)`
B. `1.26 xx 10^(-4)s_(-1)`
C. `12.6xx10^(4)s^(-1)`
D. `12.6xx10^(-4)s^(-1)`

Answer

A

Explanation

Activity of a sample is `R= | (dN)/(dt) |=|- lambda N |= lambda N = (0.6931 )/(T_(1//2)) xx m /M xx N_A`
with values , we get `R= 1.26 xx 10^4 s^(-1)`