Which term describes the representation of the number of atoms in a chemical formula?

The term that describes the representation of the number of atoms in a chemical formula is "subscript." In chemical formulas, subscripts are small numbers located to the lower right of a chemical symbol. They indicate how many atoms of that element are present in the molecule. For example, in the formula H₂O, the subscript ‘2’ next to hydrogen (H) indicates that there are two hydrogen atoms in each molecule of water.

In contrast, other terms like "symbol," "molecule," and "compound" refer to different concepts. A symbol represents a specific element (such as H for hydrogen), a molecule refers to a group of atoms bonded together, and a compound describes a substance made up of two or more different elements that are chemically combined. Understanding the role of subscripts is essential for interpreting chemical formulas accurately.