11.51 Why does the tendency for catenation decreases in the order C > Si > Ge > Sn?

The catenation depends on the strength of the element-element bond. As we move down the group 14, the element-element bond energies decrease rapidly, viz. C–C (355 kJ mol–1), Si–Si (222 kJ mol–1), Ge–Ge (167 kJ mol–1) and Sn–Sn (155 kJ mol–1), so the tendency for catenation decreases in the order C