VALENCE BOND THEORY Valence bond theory consists of – orbital overlap concept
-a covalent bond is formed due to the overlap of valence shell half filled atomic orbitals of the atom combining electron of opposite spin.
-greater the extend of overlap stronger the covalent bond is formed between two atoms.
TYPES OF OVERLAPPING
π
1)Sigma bond(σ)- overlapping takes place along the internuclear axis also k/a head on overlapping.
-extend of overlap is maximum
-electron cloud is symmetrical.
-sigma bond is stronger.
2)Pi bond(π)- overlapping takes place in side ways.
-formed after sigma bond.
-weaker than sigma bond.
-assymetrical electron cloud formed .
-a covalent bond is formed due to the overlap of valence shell half filled atomic orbitals of the atom combining electron of opposite spin.
-greater the extend of overlap stronger the covalent bond is formed between two atoms.
TYPES OF OVERLAPPING
π
1)Sigma bond(σ)- overlapping takes place along the internuclear axis also k/a head on overlapping.
-extend of overlap is maximum
-electron cloud is symmetrical.
-sigma bond is stronger.
2)Pi bond(π)- overlapping takes place in side ways.
-formed after sigma bond.
-weaker than sigma bond.
-assymetrical electron cloud formed .
