a level chemistry

user1034723

what is polarisation in simple terms

Reply 1

charco

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Original post by user1034723

what is polarisation in simple terms

Charge separation.

Atoms are neutral (no charge separation).

But when they are bonded together, one atom may attract the bonding electrons more than the other (it's said to be more electronegative)

So the electronegative atom side of the pair of atoms develops a partial negative charge while the other atom has a partial positive charge.

This separation of positive and negative charge is called a dipole (literally "two charges"), and the bond is said to be polarised.

In another sense, polarisation can also apply to the attraction of electrons by a positive charge in an otherwise non-polar system. It could also be repulsion of electrons by a negative charge causing polarisation.

The approach of a bromine molecule (itself not polar) to a double bond (large negative charge) produces polarisation of the Br-Br molecule, allowing electrophilic addition.