Answer
9.395 x 10²³ atoms
Procedure
To convert from moles to atoms, you will need to use the Avogadro's number which is equivalent to 6.0221408 x 10^23 atoms per mole.
[tex]1.56\text{ moles Ag}\frac{6.0221408\times10^{23}\text{ atoms}}{1\text{ mole}}=9.395\times10^{23}\text{ atoms}[/tex]