Solution :
On moving, down the group the size increases and electronegativity decreases, thus tendency to show catenation decreases. Decrease in catenation property is linked with $$M - M$$ bond enthalpy which decreases from carbon to tin.
Releted MCQ Question on Inorganic Chemistry >> P - Block Elements
Releted Question 1
The reddish brown coloured gas formed when nitric oxide is oxidised by air is