1. Types of Hybridisation
(a) sp hybridisation:
one s orbital mixes with one p orbital, forming two equivalent sp hybrid orbitals.
linear
180
Eg. BeCl2
two sp hybrid orbitals
50% s character
50% p character

2. Hybrid orbital: unequal size lobes unhybridised orbital:
sp Hybridisation
sp hybridisation 2s
2px
(Linear arrangement)
Hybrid orbital: unequal size lobes
2py
unhybridised
2py
2pz
unhybridised orbital:
lobes of equal size
2pz

3. Types of Hybridisation three sp2 hybrid orbitals
(b) sp2 hybridisation: one s orbital mixes with two p orbitals forming three equivalent sp2 hybrid orbitals
trigonal planar
120
Eg. BCl3
Only valence e- are used in bonding – hybridise only valence atomic orbitals
33.3% s character
66.7% p character
three sp2 hybrid orbitals

4. sp2 Hybridisation sp2 hybridisation unhybridised orbital:
Three sp2 hybrid orbitals 2s
sp2 hybridisation
2px
(Linear arrangement)
Trigonal planar arrangement
2py
2pz
unhybridised orbital:
for π bond formation or left vacant
unhybridised
2pz

5. Types of Hybridisation four sp3 hybrid orbitals
(c) sp3 hybridisation: one s orbital mixes with three p orbitals forming four equivalent sp3 hybrid orbitals.
tetrahedral
109.5
Eg. CH4
25% s character
75% p character
four sp3 hybrid orbitals

6. Tetrahedral arrangement Four sp3 hybrid orbitals
sp3 Hybridisation
Tetrahedral arrangement
Four sp3 hybrid orbitals 2s
sp3 hybridisation
2px
2py
2pz