Question -
Answer -
There are 16 electrons ina molecule of dioxygen, 8 from each oxygen atom. The electronic configurationof oxygen molecule can be written as:
Since the 1s orbital of eachoxygen atom is not involved in boding, the number of bonding electrons = 8= Nb and the number of anti-bonding orbitals = 4= Na.
Bondorder 
= 2
Similarly,the electronic configuration of 
can be written as:
Nb = 8
Na = 3
Bondorder of 
= 2.5
Electronicconfiguration of 
ion will be:
Nb = 8
Na = 5
Bondorder of =
= 1.5
Electronicconfiguration of 
ion will be:
Nb = 8
Na = 6
Bondorder of =
= 1
Bonddissociation energy is directly proportional to bond order. Thus, the higherthe bond order, the greater will be the stability. On this basis, the order ofstability is 