# The correct stability order of te following resonance structures is $I:H_2C= N^+=\bar{N} ; \quad II:H_2C^+ - N=\bar{N} \quad ; III:H_2C - N^+=\bar{N} \quad ; IV:H_2 \bar{C}- N=N^+$

$(a)\;I > II > IV >III \\ (b)\;I > III > II >IV \\ (c)\;II > I > III >IV \\ (d)\;III > I > IV >II$

(i) Number of $\pi$ bonds $\alpha$ Resonance energy $\alpha$ stability
(ii) Contributing structures should be such that negative charge resides on an electronegative element and positive charge resides o am electro positive element.
(iii) In contributing structures , like charges should not reside on atoms close to each other and unlike charges should be widely separated .
So, $I > III > II >IV$
Hence b is the correct answer