A mathmatical method whereby atomic orbitals are mixed together
to give molecular orbitals. As with hybridization,
the number of molecular orbitals produced equals the number of atomic orbitals used. For example,
mixing together the two 1s orbitals of two different H atoms (with the contribution from each of the two
orbitals varying with distance along the bond) leads to two molecular orbitals, one with lower, the other with higher
energy than the original hydrogen 1s orbitals. Electrons in the lower energy molecular orbital require input of
energy to move them into the 1s atomic orbitals, and without this added energy cannot move. They are stable and the
molecular orbital is a bonding mo. Electrons in the higher energy molecular orbital can drop into the lower energy
1s atomic orbitals spontaneously, the higher mo is destabilizing and is called an anti-bonding mo (anti = against).
Attractive forces between molecules due to the formation of instantaneous dipoles
when nuclear and electronic charge centres do not coincide due to the independent movement of nuclei and electrons
