Hybridization Rules
Determine hybrid orbital types
Steric Number Method
Steric Number = (bonding pairs) + (lone pairs)
SN = 2 → sp (linear)
Example: CO₂, BeCl₂
SN = 3 → sp² (trigonal planar)
Example: BF₃, CH₂=CH₂
SN = 4 → sp³ (tetrahedral)
Example: CH₄, NH₃, H₂O
SN = 5 → sp³d (trigonal bipyramidal)
Example: PCl₅
SN = 6 → sp³d² (octahedral)
Example: SF₆
Example: NH₃
N has 3 bonding pairs (to H) + 1 lone pair
Steric number = 3 + 1 = 4
Hybridization: sp³
Molecular geometry: trigonal pyramidal (lone pair affects shape)
Answer: sp³ hybridization
Quick Tips
- Multiple bonds (double, triple) count as ONE bonding region.
- Lone pairs on central atom count toward steric number.
- Hybridization = electron geometry; molecular geometry considers lone pairs.