The decay constant of `Ra^(226)` is `1.37xx10^(-11)s^(-1)`. A sample of `Ra^(226)` having an activity of `1.5` millicurie will contain

Options

A. `4.05 xx 10^(18)`
B. `3.7 xx 10^(17)`
C. `2.05 xx 10^(15)`
D. `4.7 xx 10^(10)`

Answer

a

Explanation

1 millicurie `= 3.7 xx 10^(7)` disintegrations per sec
1.5 millicurie ` = 5.55 xx 10^(7)` disintegration per sec
`(5.55 xx 10^(7))/(N_(0)) = lambda = 1.37 xx 10^(-11)`