Hydrocarbons are compounds that contain only carbon and hydrogen.
We shall consider in this chapter the four simplest known hydrocarbonsthose with the lowest molecular weights-and we shall see that they represent
three classes of compounds: the alkanes, in which each carbon atom has four
single bonds; the alkenes, in which two carbon atoms are joined by a double
bond (two electron pairs); and the alkynes, in which two carbon atoms are
joined by a triple bond (three electron pairs).show more...