Write the molecular orbital configuration of the following species :
` (a) N_2 " " (b) N_(2)^(+) " " (c ) N_(2)^(-) " " (d) N_(2)^(2-)`
(i) Calculate their bond orders.
(ii) Predict their magnetic behaviour.
(iii) Which of these does show highest paramagnetism?

Explanation

(a) For `N_(2)^(+)` ion, there are 9 electrons in bonding and 4 in antibonding MO `(N_(b)=9, N_(a)=4)`. Therefore, Bond order `= (N_(b)-N_(a))/(2)`
`=(7-2)/(2)`
`=2(1)/(2)`
(b) For `N_(2)^(-)` ion, there are 10 electrons in bonding and 5 in antibonding MO `(N_(b)= 10, N_(a)= 5)`. Therefore, Bond order `= (N_(b)- N_(a))/(2)`
`=(8-3)/(2) = 2(1)/(2)`