Catenation property is the property of some elements (non-metallic) of forming a long chain of atoms of same element e.g., sulphur exist as S8 molecule, P exists as P4 molecule. Catenation property is highest for carbon. It can form a chain of seven thousands of atoms. The catenation power decrease with increase in metallic character. Hence correct order is: C>>Si>Ge≈Sn>>Pb