How many atoms of Fe are in 0.26 mole of Fe?

A single gram atomic mass of iron is usually considered to be the functional equivalent of a mole of metallic iron, because iron atoms do not form well characterized polyatomic entities with themselves. Therefore, 0.26 "mole" of iron contains 0.26 X Avogadro's Number of atoms, or 1.6 X 1023 atoms, to the justified number of significant digits.