The nitrate ion NO3- is a polyatomic ion in which a nitrogen atom is bonded to three oxygen atoms and carries a negative charge. Resonance structures are different ways to represent the electron distribution in a molecule or ion, where the actual structure is an average of all possible resonance forms.For the nitrate ion, there are three resonance structures:1. In the first resonance structure, the nitrogen atom is double-bonded to one oxygen atom and single-bonded to the other two oxygen atoms. One of the single-bonded oxygen atoms carries a negative charge.O||N-O - |O2. In the second resonance structure, the nitrogen atom is double-bonded to a different oxygen atom, and single-bonded to the other two oxygen atoms. The negative charge is now on a different single-bonded oxygen atom.O - |N=O|O3. In the third resonance structure, the nitrogen atom is double-bonded to the third oxygen atom, and single-bonded to the other two oxygen atoms. The negative charge is now on the third single-bonded oxygen atom. O |N=O |O - These three resonance structures contribute to the stability of the nitrate ion in the following ways:1. Delocalization of the negative charge: The negative charge is distributed among the three oxygen atoms, which reduces the charge density on any single atom. This delocalization of charge stabilizes the ion.2. Equivalent resonance structures: All three resonance structures are equivalent in terms of energy and bond distribution. This means that the actual structure of the nitrate ion is an average of these three resonance forms, which further stabilizes the ion.3. Resonance energy: The actual structure of the nitrate ion is more stable than any single resonance structure because it is an average of all three forms. This extra stability is called resonance energy, which contributes to the overall stability of the nitrate ion.In summary, the resonance structures of the nitrate ion contribute to its stability by delocalizing the negative charge, having equivalent resonance forms, and providing resonance energy.