Answer :
(1) The hybridization of central atom beryllium in 
is, 
(2) The hybridization of central atom nitrogen in 
is, 
(3) The hybridization of central atom carbon in 
is, 
(4) The hybridization of central atom xenon in 
is, 
Explanation :
Formula used :
![\text{Number of electron pair}=\frac{1}{2}[V+N-C+A]](https://tex.z-dn.net/?f=%5Ctext%7BNumber%20of%20electron%20pair%7D%3D%5Cfrac%7B1%7D%7B2%7D%5BV%2BN-C%2BA%5D)
where,
V = number of valence electrons present in central atom
N = number of monovalent atoms bonded to central atom
C = charge of cation
A = charge of anion
Now we have to determine the hybridization of the following molecules.
(1) The given molecule is,
![\text{Number of electrons}=\frac{1}{2}\times [2+2]=2](https://tex.z-dn.net/?f=%5Ctext%7BNumber%20of%20electrons%7D%3D%5Cfrac%7B1%7D%7B2%7D%5Ctimes%20%5B2%2B2%5D%3D2)
The number of electron pair are 2 that means the hybridization will be and the electronic geometry of the molecule will be linear.
(2) The given molecule is,
![\text{Number of electrons}=\frac{1}{2}\times [4]=2](https://tex.z-dn.net/?f=%5Ctext%7BNumber%20of%20electrons%7D%3D%5Cfrac%7B1%7D%7B2%7D%5Ctimes%20%5B4%5D%3D2)
If the sum of the number of sigma bonds, lone pair of electrons and odd electrons present is equal to three then the hybridization will be, .
In nitrogen dioxide, there are two sigma bonds and one lone electron pair. So, the hybridization will be, .
(3) The given molecule is,
![\text{Number of electrons}=\frac{1}{2}\times [4+4]=4](https://tex.z-dn.net/?f=%5Ctext%7BNumber%20of%20electrons%7D%3D%5Cfrac%7B1%7D%7B2%7D%5Ctimes%20%5B4%2B4%5D%3D4)
The number of electron pair are 4 that means the hybridization will be and the electronic geometry of the molecule will be tetrahedral.
(4) The given molecule is,
![\text{Number of electrons}=\frac{1}{2}\times [8+4]=6](https://tex.z-dn.net/?f=%5Ctext%7BNumber%20of%20electrons%7D%3D%5Cfrac%7B1%7D%7B2%7D%5Ctimes%20%5B8%2B4%5D%3D6)
Bond pair electrons = 4
Lone pair electrons = 6 - 4 = 2
The number of electrons are 6 that means the hybridization will be and the electronic geometry of the molecule will be octahedral.
But as there are four atoms around the central xenon atom, the fifth and sixth position will be occupied by lone pair of electrons. The repulsion between lone and bond pair of electrons is more and hence the molecular geometry will be square planar.
