 
       
      
    Which of the following have identical bond order?
(i) 
(ii) 
(iii) 
(iv) 
The answer is the option (i)  and (ii) 
Explanation: They have identical bond order because in both of the species number of electrons in Nb = number of electrons in Nab, i.e. 14. Whereas the number of electrons in  is 17 and in 
  is 18.
