The nitrate ion NO3 has three resonance structures. In each of these structures, the nitrogen atom is at the center, and the three oxygen atoms are bonded to it. The nitrogen atom has a formal charge of +1, and one of the oxygen atoms has a formal charge of -1, while the other two oxygen atoms have a formal charge of 0. The overall charge of the ion is -1.Resonance structures of the nitrate ion NO3 are as follows:1. Structure 1: Nitrogen is double-bonded to one oxygen atom O1 and single-bonded to the other two oxygen atoms O2 and O3 . The double-bonded oxygen atom O1 has a formal charge of 0, and the single-bonded oxygen atoms O2 and O3 have a formal charge of -1.2. Structure 2: Nitrogen is double-bonded to the second oxygen atom O2 and single-bonded to the other two oxygen atoms O1 and O3 . The double-bonded oxygen atom O2 has a formal charge of 0, and the single-bonded oxygen atoms O1 and O3 have a formal charge of -1.3. Structure 3: Nitrogen is double-bonded to the third oxygen atom O3 and single-bonded to the other two oxygen atoms O1 and O2 . The double-bonded oxygen atom O3 has a formal charge of 0, and the single-bonded oxygen atoms O1 and O2 have a formal charge of -1.These resonance structures explain why all three oxygen atoms form equal bonds with the nitrogen atom. In reality, the nitrate ion does not exist as any single resonance structure but rather as a hybrid of all three structures. The electrons in the double bond are delocalized among the three oxygen atoms, resulting in a bond order of 4/3 1.33 for each N-O bond. This means that each N-O bond is somewhere between a single bond and a double bond, making them equal in strength and length. This delocalization of electrons and equal bond character is a result of the resonance phenomenon in the nitrate ion.