Answer the following question given this paragraph: 

The three smallest alkanes are methane, ethane, and propane. Some hydrocarbons have one or more carbon–carbon double bonds (denoted C=C). These hydrocarbons are called alkenes. http://catalog. flatworldknowledge. com/bookhub/reader/2547 - gobch04_s06_f02shows the formulas and the molecular models of the two simplest alkenes. Note that the names of alkenes have the same stem as the alkane with the same number of carbon atoms in its chain but have the ending -ene. Thus, ethene is an alkene with two carbon atoms per molecule, and propene is a compound with three carbon atoms and one double bond. Figure 4.7 Formulas and Molecular Models of the Two Simplest Alkenes.


Q: Methane, ethane, and propane are three of the smallest what?


A:
alkanes