Cycloalkanes (also called naphthenes, but distinct from naphthalene) are types of hydrocarbon compounds that have one or more rings of carbon atoms in the chemical structure of their molecules.  Alkanes are types of organic hydrocarbon compounds that have only single chemical bonds in their chemical structure. Cycloalkanes consist of only carbon (C) and hydrogen (H) atoms and are saturated because there are no multiple C-C bonds to hydrogenate (add more hydrogen to). A general chemical formula forpila cycloalkanes would be C_nH_2(n+1-g) where n = number of C atoms and g = number of rings in the molecule. For those cycloalkanes that have one ring in their molecules, cycloalkanes can be treated as isomers of their alkene counterparts, for example, cyclopropane and propene both have the chemical formula C₃H₆. 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.