* H₂: The subscript "2" indicates that there are two hydrogen atoms in a single molecule of water.
* O: The symbol "O" represents one oxygen atom in a single molecule of water.
Therefore, the absence of a subscript after the "O" means that there is only one oxygen atom in the molecule.
It's important to remember that chemical formulas provide a concise way to represent the composition of a molecule. The subscripts tell us the exact number of atoms of each element present in the molecule.
