Chemical formula

A chemical formula is a way that chemists describe a molecule. The formula says what atoms, and how many of each type, are in the molecule. Sometimes the formula shows how the atoms are linked, and sometimes the formula shows how the atoms are arranged in space.

The letter shows what chemical element each atom is. These are called chemical symbols and they are one or two letters long.^[1] The subscript shows the number of each type of atom. For example, methane has one carbon (C) atom and four hydrogen atoms; the chemical formula is CH₄. The sugar molecule glucose has six carbon atoms, twelve hydrogen atoms, and six oxygen atoms, so its chemical formula is C₆H₁₂O₆.

Chemical formulas are used in chemical equations to describe chemical reactions.

The 19th-century Swedish chemist Jöns Jacob Berzelius worked out this system for writing chemical formulas.

1. ↑ "chemical elements". Retrieved June 8, 2016.