Hydrocarbons are the most reduced compounds of all, with nothing
but C and H atoms. Hydrocarbons with single C-C bonds, known as
saturated hydrocarbons or alkanes, can be thought of as being built
by the snapping together of carbon tetrahedra, with unused carbon
bonding positions filled by hydrogen atoms.
There are as many different saturated hydrocarbons as there are
ways of connecting tetrahedra. The simplest are the straight-chain
alkanes (designated "n-" for "normal"), which
are shown on the opposite page.
Methane, ethane, propane, and butane are traditional names for
these compounds, but from pentane and hexane onward, the name is
derived from the Greek or Latin word for the number of carbons,
plus the suffix "-ane" to indicate a saturated hydrocarbon.
The straight-chain n-octane molecule at the bottom of the opposite
page is not the only way of constructing a C8H18