Here's how to figure out the number of atoms in a molecule of H₂SO₄ (sulfuric acid):

* H₂: The subscript "2" indicates there are two hydrogen atoms.

* S: There's no subscript, meaning there is one sulfur atom.

* O₄: The subscript "4" indicates there are four oxygen atoms.

In total, there are 7 atoms in one molecule of H₂SO₄.