hydrocarbons are organic molecules that contain only __________.
an organic compound that contains only carbon and hydrogen By definition, a compound contains at least two elements. The simplest organic compounds contain only carbon and hydrogen and are called hydrocarbons. alkane a hydrocarbon containing only single covalent bonds; alkanes are saturated hydrocarbons Methane and ethane are examples of alkanes. An alkane is a hydrocarbon in which there are only single covalent bonds. In any alkane, all the carbon-carbon bonds are single covalent bonds, and all the other bonds are carbon-hydrogen bonds.