Each of the three resonance structures of NO_3^- has how many lone pairs of electrons?

• A. 8 lone pairs
• B. 6 lone pairs
• C. 10 lone pairs
• D. 4 lone pairs

Answer: (A)

Verified step by step guidance

1. Step 1: Understand the structure of the nitrate ion (NO_3^-). It consists of one nitrogen atom bonded to three oxygen atoms, with an overall charge of -1.
2. Step 2: Recall that resonance structures are different valid Lewis structures that represent the same molecule, differing only in the placement of electrons, not atoms.
3. Step 3: Draw one resonance structure of NO_3^- by placing a double bond between nitrogen and one oxygen, and single bonds between nitrogen and the other two oxygens. Assign formal charges accordingly.
4. Step 4: Count the lone pairs on each oxygen atom. Oxygen atoms typically have 6 valence electrons, and lone pairs are the non-bonding pairs of electrons around an atom. Remember to include lone pairs on all oxygens in the structure.
5. Step 5: Since all three resonance structures are equivalent except for which oxygen has the double bond, the total number of lone pairs on the three oxygens combined remains the same in each resonance structure. Sum the lone pairs on all oxygens to find the total number of lone pairs in each resonance structure.