Intermolecular forces are forces between molecules. They are much weaker than covalent, ionic or metallic bonds. Let's learn about them in A-Level Chemistry!
Permanent Dipole –Permanent Dipole
Permanent dipoles occur when a molecule has two atoms bonded together which have substantially different electronegativities so that one atom attracts the shared electrons much more than the other.
Molecules with a permanent dipole are polar molecules.
One side of the molecule is positive, one is negative.
Instantaneous Dipole –Induced Dipole
These forces cause all atoms and molecules to be attracted to each other. They are the weakest type of intermolecular bonding.
Electrons in charge clouds are always moving really quickly. At any one moment, the electrons in an atom are likely to be more to one side than the other.
At this moment, the atom has a temporary dipole.This dipole can create another temporary dipole in the opposite
direction on a neighbouring atom. The two dipoles are then attracted to each other.
Permanent Dipole –Induced Dipole
This intermolecular bonding occurs when a permanent dipole induces a dipole in another molecule, then the two attract one another.
This kind of bonding occurs between HCl and Cl2 molecules.
Drafted by Eunice (Chemistry)
References:
https://ibchem.com/IB16/02.42.htm
https://www.chem.purdue.edu/gchelp/liquids/disperse.html
https://www.chemistrylearner.com/chemical-bonds/dipole-dipole-forces