* Identify the number of oxygen atoms per molecule: The formula H₂SO₄ tells us there are 4 oxygen atoms in each molecule of sulfuric acid.

* Multiply by the number of molecules: You have 5 molecules of H₂SO₄.

* Calculate the total: 4 oxygen atoms/molecule * 5 molecules = 20 oxygen atoms

Therefore, there are 20 oxygen atoms in 5 molecules of H₂SO₄.