To determine the bond order and bond length of the nitrogen-oxygen bond in the nitrate ion NO3- , we need to first examine its resonance structures and molecular orbital theory.Resonance Structures:The nitrate ion has three resonance structures, where each oxygen atom forms a double bond with the nitrogen atom in one of the structures, and the other two oxygen atoms form single bonds. The actual structure of the nitrate ion is a hybrid of these three resonance structures.Bond Order:Bond order is defined as the number of bonding electrons minus the number of antibonding electrons, divided by 2. In the case of the nitrate ion, the bond order can also be calculated by dividing the total number of bonds by the number of resonance structures.Total number of bonds in NO3- = 1 double bond + 2 single bonds = 1 2 + 2 1 = 4Number of resonance structures = 3Bond order = Total number of bonds / Number of resonance structures = 4 / 3 1.33Bond Length:As the bond order increases, the bond length typically decreases. In the case of the nitrate ion, the bond order is between a single bond 1 and a double bond 2 , so the bond length will be between the typical lengths of a nitrogen-oxygen single bond and a nitrogen-oxygen double bond.A nitrogen-oxygen single bond N-O has a bond length of approximately 1.47 angstroms , while a nitrogen-oxygen double bond N=O has a bond length of approximately 1.23 .Since the bond order is closer to a single bond 1.33 , the bond length of the nitrogen-oxygen bond in the nitrate ion will be closer to the single bond length. However, the exact bond length may vary depending on the specific environment and other factors.In summary, the bond order of the nitrogen-oxygen bond in the nitrate ion NO3- is approximately 1.33, and the bond length is between 1.23 and 1.47 , likely closer to the single bond length.