The nitrate ion NO3- is a polyatomic ion with a central nitrogen atom surrounded by three oxygen atoms. It has a negative charge due to the presence of an extra electron. The possible resonance structures of the nitrate ion can be represented as follows:1. Structure 1: 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 the negative charge.O||N-O - |O2. Structure 2: The nitrogen atom is double-bonded to a different oxygen atom and single-bonded to the other two oxygen atoms. One of the single-bonded oxygen atoms carries the negative charge.O - |N-O||O3. Structure 3: The nitrogen atom is double-bonded to the third oxygen atom and single-bonded to the other two oxygen atoms. One of the single-bonded oxygen atoms carries the negative charge. O |N-O||O - These three resonance structures contribute to the overall electronic structure of the nitrate ion by delocalizing the negative charge and the double bond among the three oxygen atoms. This delocalization of electrons results in the stabilization of the nitrate ion, as the negative charge is spread out over the entire molecule rather than being localized on a single atom.In reality, the actual structure of the nitrate ion is a hybrid of these three resonance structures, with each oxygen atom having a partial double bond character and an equal distribution of the negative charge. This hybrid structure results in the nitrate ion having equivalent bond lengths and bond strengths for all three N-O bonds, which is consistent with experimental observations.