first you need to solve for the number of moles in each. 1 mole of anything = atomic mas of that element (g)
Carbon has an atomic mass of 12.0107 1 mole of Carbon = 12.0107 g
Iron has an atomic mass of 55.845 1 mole of Iron = 55.845 g
now convert each from grams to moles (grams of Carbon cancel and you are left with moles of carbon) 100.0 g Carbon x 1 mol Carbon = 8.326 mol Carbon 12.0107 g Carbon
(grams of Iron will cancel and you are left with moles of iron) 100.0 g Iron x 1 mol Iron = 1.791 mol Iron 55.845 g Iron
now we can use avogadro's number to solve for the amount of atoms in each 1 mol = 6.02x10^23 atoms
8.326 mol Carbonx 6.02 x 10^23 atoms = 5.012 x 10^24 atoms Carbon 1 mol Carbon 1.791 mol Iron x 6.02 x 10^23 atoms = 1.078 x 10^24 atoms Iron 1 mol Iron 5.012 x 10^24 atoms Carbon > 1.078 x 10^24 atoms Iron
