The number of atoms in 1.00 grams of Ag is calculated as below
calculate the moles of Ag = mass/molar mass
= 1g/ 107.87 g/mol= 9.27 x10 ^-3 moles
by use of Avogadro law constant 1 mole = 6.02 x10^23 atoms
what about 9.27 x10 ^-3 moles
= (9.27 x10^-3 moles/ 1mole) x6.02 x10 ^23 atoms = 5.581 x10^ 21 atoms