In a chemical formula, what do subscripts represent?

In a chemical formula, subscripts are used to indicate the number of atoms of each element present in a molecule. For instance, in the formula H₂O, the subscript "2" next to the hydrogen (H) indicates that there are two hydrogen atoms for every one oxygen atom (O). This numerical representation is essential for understanding the composition of the substance and helps in balancing chemical equations, calculating molar masses, and predicting how substances will react with one another.

The other options do not accurately describe the function of subscripts in chemical formulas. The type of bond present is determined by the nature of the elements involved and is not indicated by subscripts. The number of molecules in a compound is typically represented by a coefficient in front of the formula, not by subscripts. Lastly, while subscripts provide information about the number of atoms, they do not convey the arrangement of those atoms, which is determined by molecular geometry and other structural factors.