SP3 HYBRIDIZATION AND SHAPES OF METHANE AND ETHAN MOLECULES, Simple concept of unpaired valence electrons can explain number

 

Simple concept of unpaired valence electrons can explain number of covalent bond formed in nitrogen, oxygen and fluorine only in second period and it cannot explain number of covalent bond formed in beryllium, borrow and carbon of the same period. All these elements can form covalent bonds and number of covalent bond formed is greater than the number of unpaired electrons present in the ground state electronic configuration of that element that is why orbital hybridization is also called expansion of octect.  These are many types of orbital hybridization like mixing of s and p orbitals indifferent proportion or mixing of d or f orbitals with s and p orbitals, all mixing combinations depends upon the situation.

 

SP3  HYBRIDIZATION AND SHAPES OF METHANE AND ETHAN MOLECULES:

 

            Group state configuration of carbon is; 

Carbon atom in Methane and Ethane molecules have four identical covalent bonds. It is possible due to promotion of one electron from 25 to empty 2p orbital. This mixing of orbitals and promotion of electron to expend its octet is called orbital hybridization.

             Hybride configuration (excited state) of carbon is.

In this kind of orbital mixing one s-orbital and three p-orbitals are involved this is why it is called sp³ hybridization and as a result generate four degenerate orbitals of same energy and same shape which are oriented three dimensionally (3D) in molecules sp³ hybride orbitals have tetrahedral arrangement and apart from each other at an angle of 109.5⁰.

shape of Methane Molecula