$\begin{aligned} & \text { Volume of silver coating }=0.05 \times 0.05 \times 10000=25 \mathrm{~cm}^3 \\ & \text { Mass of silver deposited }=25 \times 7.9 \mathrm{~g} \\ & \text { Moles of silver atoms }=\frac{25 \times 7.9}{108} \\ & \text { Number of silver atoms }=\frac{25 \times 7.9}{108} \times 6.023 \times 10^{23} \\ & =11.01 \times 10^{23} \quad \text { Ans. } 11\end{aligned}$