CHEMICAL TERMS

Do not capitalize or hyphenate compounds as nouns.

Hyphenate as adjectives only if necessary for clarity:

            carbon dioxide

            carbon dioxide test

            carbon monoxide fumes

            iron-oxide red

Hyphenate elements with mass numbers:

            strontium-90

            strontium-90 fallout

            Sr-90

            carbon-14

            C-14

            carbon-14 dating

Use an inferior number after an element to indicate the number of atoms in a molecule:

            CO2        H2O

In technical papers, use a superior number before an element to indicate the mass number:

            18O