3.1.3.6 bond polarity

What is electronegativuty

Power of an atom to attract the pair of electrons in a covalent bond

What is the electron distribution like in a covalent bond betwee different elements and what does it produce

Unsymmetrical

It produces a polar covalent bond and may cause a molecule to have a pemanent dipole

What does electronegativity depend on

Nuclear charge

Sheilding

Distance from nucleus

What is the trend in electrongetaiviy up a group

E.n increases

Atoms get smaller and there is less sheilding

What is the most electronegative element

Fluorine

Why does electronegativity increase acr0s period

Atomic radius decreases so stronger attraction between positive nucleus and 2 electrons in covalent bond

Nuclear charge increases and so greater attraction

If there is no difference o very small difference in E.N then the compound is

Non polar for example cl2

A very large difference is e.n results in

Ionic compound

E.g NaCl

Give an example of a molecule that has polar bonds but is non polar

Carbon dioxide

This is because polarities are equal (arranged symmetrically and both are c=o so Polarities cancel out

Give. 4 examples of different molecules that cancel out