5 g of radioactive- species having molar mass 200 undergoes decay with decay constant of `lambda`. The initial specific activity can be given by :

Options

A. `3 xx 10^(23) lambda` dps
B. `3 xx 10^(24) lambda` dps
C. `3 xx 10^(21) lambda` dps
D. `3 xx 10^(30) lambda` dps

Answer

C

Explanation

Specific activity = activity shown by 1 g species = rate shown per g by species
Activity `= lambda. N = (lambda.N_(A))/(M) = (6 xx 10^(23))/(200) = lambda xx3 xx 10^(21)` dps, where N is no. of atoms is 1 g