Q.

The decay constant for a radioactive nuclide is 1.5×10-5 s-1. Atomic of the substance is 60 g mole-1, (NA=6×1023). The activity of 1.0 μg of the substance is _________ ×1010 Bq.                   [2023]


Ans.

(15)

λ=1.5×10-5 s-1

Number of mole=1×10-660=10-76

No. of atoms=no. of moles×NA

                          =10-76×6×1023=1016

A=Nλe-λt

For t=0, A0=N0λ=1.5×10-5×1016=15×1010 Bq