What is the relationship between electronegativity and cation polarizability?

Moderators: Chem_Mod, Chem_Admin

305144105
Posts: 32
Joined: Thu May 10, 2018 3:00 am

What is the relationship between electronegativity and cation polarizability?

Postby 305144105 » Thu Nov 29, 2018 10:21 am

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?

Chem_Mod
Posts: 16977
Joined: Thu Aug 04, 2011 1:53 pm
Has upvoted: 364 times

Re: What is the relationship between electronegativity and cation polarizability?

Postby Chem_Mod » Thu Nov 29, 2018 12:18 pm

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.


Return to “Electronegativity”

Who is online

Users browsing this forum: No registered users and 0 guests