CHEMISTRY COMMUNITY

What is the relationship between electronegativity and cation polarizability?

Electronegativity: measure of how strongly atoms attract bonding electrons to themselves

Polarizability: measure of how easily an electron cloud (belonging to an atom/molecule/ion) is distorted by an electric field (caused by electrode/cation/anion).

Are the two related at all or unrelated?
Why is it not correct to assume that cations with high electronegativity have low polarizability?
Ex. Why is O2- more polarizable than N3-, even though it is more electronegative?

We don't typically use polarizability to describe cations; instead, we use polarizing power. Polarizing power refers to a cation's ability to distort an anion's electron cloud. A cation has higher polarizing power if it has a higher charge and/or is smaller (because positive charge is distributed over a smaller area).

Polarizability refers to how easily an anion's electron cloud is distorted. The less electronegative / the larger the anion is, the easier its cloud is going to be distorted because those electrons are less tightly bound.

N3- is more polarizable than O2- because like you said, oxygen is more electronegative and has a higher effective nuclear charge.