The order of relative stability of the contributing structure is :
Choose the correct answer from the options given below :

Solution

Chemistry ma’am · 3 steps

Rank resonance structures by charges: none is best, then charges that suit electronegativity.

1. Ranking rules. A neutral structure with full octets contributes most. If charges must appear, the structure is better when the negative charge sits on the more electronegative atom. It is worst when a highly electronegative atom carries a positive charge with an incomplete octet.

   Structure	Charges	Octets	Verdict
   I	none	all atoms complete	most stable
   II	+ on C, - on O	terminal C has only 6	charge separation, but - is on the electronegative O
   III	- on C, + on O	O has only 6	least stable: + on the electronegative atom, and it lacks an octet

2. Compare II and III. Both separate charge across the same atoms. Oxygen is more electronegative than carbon, so it carries the negative charge well in II. Forcing a positive charge and a sextet onto oxygen in III makes it the poorest contributor.
3. So. The order of stability is I > II > III, which is option (b).

The idea to keep. To rank resonance structures, ask in order: full octets? fewest charges? negative charge on the more electronegative atom? Positive charge on oxygen with a sextet is almost always the worst.

Answer from the NTA final answer key. Solution by PrepWiser.