# What is meant by term bond order? Write bond orders for N2, O2?

The bond order shows the number of chemical bonds present between a pair of atoms. The Bond Order Formula can be defined as half of the difference between the number of electrons in bonding orbitals and antibonding orbitals.

Bond order formula is given as below

$$\begin{array}{l}Bond order = \frac{1}{2}\left [ a – b \right ]\end{array}$$

where

a = Number of electrons in bonding molecular orbitals.

b = Number of electrons in antibonding molecular orbitals.

(i) Structure of N2

Electronic configuration of N2 (14 electrons) = KK'(σ2s)(σ*2s)2 (π2Px)2 (π2py)(σ2pz)2

a = 10

b= 4

Bond order = 1/2 (10 – 4)

Bond order = 3

(ii) Structure of O2

Electronic configuration of O2(16 electrons) = [σ(1s)]2(1s)]2[σ(2s)]2(2s)]2[σ(1pz)]2[π(2px)]2[π(2py)]2(2px)]1(2py)]1

a = 10

b = 6

Bond order = 1/2 (10 – 6)

Bond order = 2