Question

what is hybridization;explain it with the help of ammonia and methane?

Answer 1

 chemistry, orbital hybridisation (or hybridization) is the concept of mixing atomic orbitals into new hybrid orbitals (with different energies, shapes, etc., than the component atomic orbitals) suitable for the pairing of electrons to form chemical bonds in valence bond theory. Hybrid orbitals are very useful in the explanation of molecular geometry and atomic bonding properties. Although sometimes taught together with the valence shell electron-pair repulsion (VSEPR) theory, valence bond and hybridisation are in fact not related to the VSEPR model.
Hybridization in Methane & Ethane –

one s and three p orbitals hybridise to form four equivalent sp3 hybrid orbitals. These are singly filled and directed towards four corners of regular tetrahedron . These four sp3 hybrid orbitals form sigma bond with singly filled s-orbital of H- atom and four sigma bonds are formed. Bond angle is 109028′ and geometry is tetrahedral.

Hybridization in Ammonia –

7N- 1s2,2s2,2p3

 There four sp3 hybrid orbitals of nitrogen atom of  ammonia is formed by the overlapping of three half filled orbitals of  Nitrogen atom with s-orbital of 3 hydrogen atoms. There remains a full-filled sp3 hybrid orbital.

Geometry of  ammonia is pyramidal or distorted tetrahedral  due to presence of lone pair. There is lp-bp and  bp-bp repulsion.