Illustrated Glossary of Organic Chemistry

Molecular formula (chemical formula): A list of all the elements, plus how many atoms of each element, are present in a chemical compound. The number of atoms is indicated with a subscript after the element's symbol, except when only one atom of an element is present; in this case no subscript is used. For example methane has a molecular formula of CH4, indicating it contains one carbon atom and four hydrogen atoms.

The Hill system is generally used for organic compounds. In this system, the correct molecular formula format is: carbon, hydrogen, then all other elements in alphabetical order.

When a molecule has bonding other than covalent, groups of atoms such as complex anions or waters of hydration are usually listed together.

Molecular formula

Glucose C6H12O6

Copper (II) sulfate pentahydrate