There are many of carbon compounds. A large number are found in , while others are produced in the laboratory.
Carbon forms more compounds that other elements because:

1	although most bonds between identical atoms are rather weak, the C-C bond is , which means carbon can form long of carbon atoms.
2	carbon is one of a very few elements that can form or bonds.
3	carbon has a valency of , which increases the number of different compounds it can make.

To make sense of the millions of carbon compounds, we group them into families called series.
Each member of the same series has:

a	the same group
b	common properties
c	similar or graded properties
d	a common formula (eg alkanes: CnH2n + 2)
e	each member of the series is larger by one group than the previous one.