Nomenclature of Chemical substance International Union of Pure and Applied Chemistry (IUPAC) The IUPAC name of an alkane with an unbranched chain of carbon atoms consists of two parts: a prefix that indicates the number of carbon atoms in the chain; the ending that indicates the species Nomenclature of Hydrocarbon Prefixs used in the IUPAC system to indicate one to 20 carbon atoms in a chain Nomenclature of Hydrocarbon 烷烃（Alkanes ）：-ane 甲烷methane, 乙烷ethane, 己烷hexane 烷烃基（烷基alkyl ） 方法：删去-ane ，加上-y
