Question

What is inert pair effect?

Answer 1

Inert pair effect was proposed by a scientist called Sidgwick. Sidgwick proposed the shape of the several molecules with the help of Powell and Sidgwick also correlated the shape of the molecules with their physical properties.

Complete answer:
- In the question it is asked what inert pair effect is.
- Inert pair effect means the affinity of electrons in the outermost s-orbital to remain unionized (not going to be donated) in the compounds.
- We can see this inert pair effect in p-block elements (non-metallic compounds).
- This property is due to the poor shielding effect of the electrons in d and f orbitals.
- Due to inert pair effect lower oxidation of the few p block elements are more stable than the higher oxidation states of the elements.
- By using inert pair effects we can understand why few common elements like lead won’t follow the octet rule.
- We can see this inert pair effect commonly in VI, V, Vi groups that are followed by the d-block (transition elements).
- The elements which show the property of the inert pair effect are Tin (Sn), Lead (Pb), Bismuth (Bi) and Thallium (Th). These elements have less affinity to lose their electrons from valence s-shell.

Note: The element Thallium belongs to the 13th group in the periodic table exhibits two oxidation states +1 and +3. But +1 oxidation of the element Thallium is more stable than the +3 oxidation due to inert pair effect.