What are the important features of valence bond theory?

Explanation

The postulates of valecne bond theory
(i) The central metal atom/ion makes available a number of vacant orbitals to its coordination number
(ii) These vacant orbitals form covalent bonds with the ligand orbitals
(iii)A covalent bond is formed by the overlap of a vacant metal orbital and filled ligand orbitals.This complete overlap leads to the formation of a metal ligand ` sigma ` (sigma) bond
(iv) A strong covalent bond is formed only when the orbitals overlaps to the maximum extent.
(v) This maximum overlapping is possible only when the metal vacant orbitals undergo a process called 'hybridisation'
(vi ) A hybridation orbitals has a better directional characteristics than an unhybridised one.The following table gives the coordination number orbitals hybridisation and geometry of the complexex.

Magnetic moment
The paramagnetic moment is given by the following spin-only formula
` mu =sqrt( n(n+2) ) NM`
BM =Bohr magneton
` mu _s` =spin -only magnetic moment
n= number of unpaired electrons.