a
એક્ટિવીટી \(R\,\, = \,\,\lambda N\,\, = \,\,\lambda \,\, \times \,\,\left( {\frac{M}{{{M_\omega }}}\,\, \times \,\,{N_A}} \right)\,\,\)

\(\, = \,\,(1.6\,\, \times \,\,{10^{ - 5}}{s^{ - 1}})\,\,\,\left( {\frac{{{{10}^{ - 3}}g}}{{64\,\,g}}\,\, \times \,\,6\,\, \times \,\,{{10}^{23}}} \right)\,\,\)

\(\, = \,1.5\,\, \times \,\,{10^{14}}\,dps\,\, = \,\,1.5\,\, \times \,\,{10^{14}}\,\,Bq\,\)

\(\, = \,\,\frac{{1.5\,\, \times \,\,{{10}^{14}}}}{{3.7\,\, \times \,\,{{10}^{10}}}}\,\,Ci\,\, = \,\,4054\,\,Ci\)