Question

The element that does not show catenation is:
(A) Pb
(B) Ge
(C) Si
(D) Sn

Answer 1

As we all know that catenation property is defined as the bonding of atoms of the same element in a chain like manner. It occurs mostly in the carbon family and catenation power of the carbon family is higher than the boron family and nitrogen family. Down the catenation tendency decreases.

Complete Step by step answer: As we have learnt that catenation is basically the bonding of atoms of same element in a chain like manner and is common in carbon family because organic chemistry is based on mostly carbons and carbons are covalently bonded together to form a bigger chain and even complex structures as well.
We should know that catenation is majorly based on bond energy of the element and it decreases when elements with overlapping subshell form bonds. That is the reason that carbon having least diffused or overlapped p-orbital have the ability to form long p-p σ-bonds.
Let us discuss the given options one by one as they all belong to the carbon family only. Silicon can bond with other silicon atoms and results in the formation of disilane which is the parent but where the number of silicon atoms increase in a chain it becomes difficult to prepare and even isolate the compound because their thermal stability decreases whenever the silicon atoms increase in number.
Next is germanium, this is normally not known to catenate much but recently germanium along with silicon and arsenic etc are reported in making double and triple bonds between semi-metallic elements. Tin is similarly not known to but is a topic of research to identify the catenation property in it but it is equivalent to germanium.
Lastly, lead or Pb which is a metal in the group and catenation property is mostly shown by non-metals that is why it does not show any catenation power.

Thus, the correct answer is (A) that is Pd does not show any catenation power.

Note: catenation tendency is higher in carbon while silicon comes second highest following germanium and tin which show very less catenation so we can arrange them in decreasing tendency of catenation as: C>>Si>Ge=Ge. This kind of order can be asked in exams.