Answer:
Divide the atoms of sulfur by avogadro's number (6.02 x 10^23 mol)
(1.21 x 10^21) / (6.02 x 10^23)
= 0.00200996678
Molar mass of Sulfur (listed in your periodic table) = 32.06g/mol
moles = mass/molar mass
mass = molar mass x moles
Mass of Sulfur = (32.06) x (0.00200996678) = 0.06g of Sulfur
