Functional groups are certain groups of atoms that react in a predictable way. Although organic compounds are based on hydrocarbon chains, the addition of a functional group often brings other types of atoms, such as oxygen or nitrogen. When drawing organic compounds, keep in mind that carbon atoms form four bonds. These bonds can be a combination of single bonds, double bonds, or triple bonds, to make a total of four bonds. For instance, a carbon atom could form four single bonds, or a single bond and a triple bond, or a double bond and two single bonds. A hydrogen atom is removed from the first carbon atom of a butane molecule and is replaced by a hydroxyl group. Draw the new molecule formed. Draw the molecule on the canvas by choosing buttons from the Tools (for bonds), Atoms, and Advanced Template toolbars. The single bond is active by default.