Question
Define catenation. How will you explain the tendency for catenation decreases in the order C > Si > Ge > Sn > Pb?
Solution
The property of self-linking of atoms of an element through covalent bonds to form straight or branched chains and rings of different sizes is called catenation. The tendency of an element to form chains depends on upon the strength of the element-element bond. Amongst the group 14 elements, C-C bond strength (355 kJ mol1) is maximum, therefore, carbon shows maximum tendency for catenation. As we move down the group, the element-element bond strength decreases very rapidly i.e. C-C (355 kJ mol-1), Si-Si (215 kJ mor1), Ge-Ge (165 kJ mol–1), therefore, the tendency for catenation decreases in the order C > Si > Ge. In fact, tin and lead do not show catenation.
