what is meant by the term chemical formula

A chemical formula is a symbolic representation of the composition of a chemical compound or molecule, using chemical element symbols, numbers, and sometimes other symbols such as parentheses, dashes, brackets, commas, and plus (+) and minus (−) signs. It identifies each constituent element by its chemical symbol and indicates the proportionate number of atoms of each element. A chemical formula is not a chemical name since it does not contain any words. There are different types of chemical formulas, including empirical, molecular, structural, and projection formulas. An empirical formula consists of symbols representing elements in a compound and subscripts indicating the relative number of atoms of each constituent element. A molecular formula shows the exact number of atoms of each element in a molecule. A structural formula shows the arrangement of atoms in a molecule and how they are bonded together. A projection formula is a simplified structural formula that shows the arrangement of atoms in a molecule in a two-dimensional way. Chemical formulae can be used in chemical equations to describe chemical reactions and other chemical transformations.