There are three resonance structures that can be drawn for the nitrate ion NO3- . In each resonance structure, the nitrogen atom is at the center, and the three oxygen atoms are bonded to it. One of the oxygen atoms has a double bond with the nitrogen atom, while the other two oxygen atoms have single bonds. The double bond and single bonds rotate among the three oxygen atoms in the different resonance structures.Resonance Structure 1:- N=O bond length: ~1.24 shorter due to double bond - N-O bond length: ~1.36 longer due to single bond - Partial charges: Nitrogen + and double-bonded oxygen - , single-bonded oxygens have a full negative charge -1 Resonance Structure 2:- N=O bond length: ~1.24 shorter due to double bond - N-O bond length: ~1.36 longer due to single bond - Partial charges: Nitrogen + and double-bonded oxygen - , single-bonded oxygens have a full negative charge -1 Resonance Structure 3:- N=O bond length: ~1.24 shorter due to double bond - N-O bond length: ~1.36 longer due to single bond - Partial charges: Nitrogen + and double-bonded oxygen - , single-bonded oxygens have a full negative charge -1 In reality, the bond lengths and charges are an average of these resonance structures. The actual N-O bond length in the nitrate ion is ~1.28 , which is intermediate between the single and double bond lengths. The partial charges on the nitrogen and oxygen atoms are also averaged, with the nitrogen having a partial positive charge and the oxygen atoms having partial negative charges.