Representative particles help.

(b) 7.18 10-3 mol sodium chloride
formula units

(c) 22.2 mol carbon dioxide
molecules

(d) 0.462 mol nitrogen (N2)
molecules

Those are the correct representative units. Do you want to know how many are in the given number of moles? If so, multiply the moles by Avogadro's Number. If you wanted to know the total number of atoms, you'd do the first step I described, then multiply that answer by the number of atoms in a given representative unit.