Question

Inert pair effect is more prominently seen in:
A. Nitrogen
B. Bismuth
C. Phosphorus
D. Antimony

Answer 1

Hint: The inert pair effect is defined as the tendency of the two electrons in the outermost s-orbital to be unshared in the compounds of the post transition elements and due to this these ns electrons remains more tightly held by the nucleus and hence participate less in the bond formation. By properly understating the above definition of the inert pair effect, try to find out the element from the above in which we can observe more prominent inert pair effects.

Complete step by step answer:
The pair of electrons in the valence s-orbital is reluctant to take part in bond formation due to poor shielding effect of d-electrons and f-electrons in heavier elements. It is called inert pair effect due to which lower oxidation state becomes more stable than higher oxidation state in case of p-block elements. The inert pair effect is generally exhibited by some heavier nucleus p-block elements with common molecular formula $n{{s}^{2}}n{{p}^{1-6}}$ such as $Tl,\text{ }Sn,\text{ }Pb,\text{ }Bi,\text{ }Po$ etc these elements have a less tendency to leave their outer most s-electrons when a chemical reaction takes place.
The inert pair effect is commonly seen in elements of ${{6}^{th}}$ and ${{7}^{th}}$ periods.
From the above given elements Bismuth is the element that belongs to the ${{6}^{th}}$ period.

Therefore inert pair effect is more prominently seen in Bismuth, which is option B.

Note: The consequences of the inert pair effect are:
1. Stability of the electrons and compounds changes due to inert pair effect.
2. Inert pair effects cause the variable valency of the elements.
3. It influences the oxidizing and reducing properties of the compounds.
4. It also affects the melting and boiling point of the elements.