Cycloalkanes (also called naphthenes) are chemical compounds with one or more carbon rings to which hydrogen atoms are attached according to the formula CnH2n. Cycloalkanes with a single ring are named analogously to their normal alkane counterpart of the same carbon count: cyclopropane, cyclobutane, cyclopentane, cyclohexane, etc. The larger cycloalkanes, with greater than 20 carbon atoms are typically called cycloparaffins.