Which has more atoms: 3.0 g of iron, or 2.0 g of sulfur?

You must calculate the molar quantity of each element. Moles relate to the number of species. If there are 1 mole of particles, there are $6.022 \times {10}^{23}$ individual particles.
Moles of iron, $\frac{3.0 \cdot \cancel{g}}{55.85 \cdot \cancel{g} \cdot m o {l}^{-} 1}$ $=$ ??mol
Moles of sulfur, $\frac{2.0 \cdot \cancel{g}}{32.06 \cdot \cancel{g} \cdot m o {l}^{-} 1}$ $=$ ??mol