Answer:
12 Oxygen Atoms
Explanation:
We need to figure out how many atoms of Al, S and O are represented by the these two similar formulas:
Al2(SO4)3:
Al2 means 2 aluminums, (SO4)3 means 3 (SO4)s. The grand tally: 2 aluminum atoms + 3 sulfur atoms + 12 oxygen atoms = 17 atoms total in each molecule.
Hope this helps!
