Covalent compounds are different than ionic compounds in that they share electrons to reach a more stable state. Sometimes, they can form molecules in different numbers of ratios of the same two elements, such as sulfur and oxygen.

The following table describes possible combinations of sulfur and oxygen. Click on each cell in the table to learn more.

All three formulas have the same elements present in different ratios and, as a result, are different compounds. Sulfur monoxide is very flammable, while the other two are not.

In chemistry, it is necessary to have a set of naming rules to distinguish compounds and make sure the same “language” is spoken in terms of the chemical makeup. Scientists currently follow IUPAC naming rules for nomenclature.

In the next two sections, you will learn more about naming covalent compounds.