Answer
$$2.11\times10^{22} atoms Ag$$
Work Step by Step
1. Use the molar mass of silver and Avogadro's number as conversion factors in order to determine the number of silver atoms in the sample.
2. $3.78 g Ag\times\frac{1 mol Ag}{107.8683 g Ag}\times\frac{6.022\times10^{23}}{1 mol Ag} = 2.11\times10^{22} atoms Ag$
