Iron has an atomic mass of 55.845 g/mol, so the amount of iron in 65.0 g is 65.0/55.845 = mol.
Avogadro's law states that in every mole of a substance, there are [tex]6.022 \times 10^{23}[/tex] particles per mole, so in this case, that means there are [tex](1.16393589)(6.022 \times 10^{23})=\boxed{7.01 \times 10^{23}} \text{ atoms (to 3 sf)}}[/tex]
