The electron pairs surrounding the central atom repel one another and move so far apart from one another that there are no further repulsions between them. As a result, the molecule has minimum energy and maximum stability.

If the central atom is linked to similar atoms and is surrounded by only bond pairs of electrons, repulsions between them are similar. As a result, the shape of the molecule is symmetrical and the molecule is symmetrical and the molecule is said to have a regular geometry.

If the central atom is linked to different atoms or is surrounded by bond pairs as well as lone pairs of electrons, the repulsions between them are different. As a result, the molecule has an irregular or distorted geometry. The order of repulsions between electron pairs is as follows:

Be ClCl

Be

120o109.5o

90o

180o

Bond Angles

Px

Py

Pz

Px

Py

Pz

2s 2px 2pz2py1s sp3 sp3 sp3 sp3

109.5o

Promote Hybridize

x

z

y

Methane: Carbon

2s 2px 2pz2py1s sp2 sp2 sp2

120o

Hybridized

Formaldehyde: Carbon

Promoted

120o

TrigonalPlanar

2s + 2px + 2pz

2s 2px 2pz2py1s sp2 sp2 sp2

120o

Hybridized

Formaldehyde: Oxygen

120o

TrigonalPlanar

Lone PairsLone Pairs

2s + 2px + 2pz

Formaldehyde

Sigma bond2 Lone Pairs2 Lone Pairs bondbond

2s 2px 2pz2py1s sp spPromoted Hybridized

Hydrogen Cyanide: Carbon

2s + 2px

Linear

2s 2px 2pz2py1s sp spHybridized

Hydrogen Cyanide: Nitrogen

2s + 2px

Linear

bondbond

bondbond

3s 3px 3pz3py2

Neon

120o

Hybridized

Phosphorus Pentachloride: Phosphorus

TrigonalBipyrimidal

sp3d sp3d sp3d sp3d sp3d

dxz dyz dxy dx2-y2 dz2

120o

90o

Promoted