Catenation:
One of the remarkable property of carbon atom is its unique capacity to form bonds with other carbon atoms. This property of forming bonds with atoms of the same element is called catenation. Carbon shows maximum catenation in its group. This is because of the larger strength of carbon to carbon bond as compared to that of other atoms. For example, C—C bond is very strong (335 kJ/mol) in comparison to Si—Si bond (220 kJ/mol) or Ge—Ge bond (167 kJ/mol). As a result, carbon atoms can link with each other to form either linear chains of various lengths or branched chains and even rings of different sizes as shown below:
