In chemistry, subscripts are used after an element symbol to indicate the number of atoms present in a molecule or compound.
Chemical Formula: A representation using symbols and numbers to describe types and numbers of atoms present in one unit of a substance.
A substance formed when two or more elements chemically bond together, indicated by their fixed ratio presented through subscript(s).
The number unique to each element representing its position on periodic table; it also indicates number protons found within nucleus.