To determine which contains more atoms, we need to calculate the number of moles for each element using their respective molar masses and compare.

Iron (Fe):

- Molar mass of Fe = 55.845 g/mol

Number of moles in 56g of Fe = 56 g / 55.845 g/mol = 1 mole

Sulfur (S):

- Molar mass of S = 32.066 g/mol

Number of moles in 16g of S = 16 g / 32.066 g/mol = 0.5 moles

Comparing the number of moles:

1 mole of Fe contains 6.022 x 10^23 atoms (Avogadro's number)

0.5 moles of S contains 0.5 x 6.022 x 10^23 atoms = 3.011 x 10^23 atoms

Therefore, 56g of Fe contains more atoms than 16g of S.