How many resonance structures can be drawn for the nitrate ion, `NO_3^(-)`?

Options

A. 1
B. 2
C. 3
D. 4

Explanation

To determine how many resonance structures can be drawn for the nitrate ion, \( \text{NO}_3^{-} \), we can follow these steps:

### Step 1: Draw the Lewis Structure of the Nitrate Ion
1. Count the total number of valence electrons:
- Nitrogen (N) has 5 valence electrons.
- Each Oxygen (O) has 6 valence electrons, and there are three Oxygens: \( 3 \times 6 = 18 \).
- The negative charge adds 1 extra electron.
- Total: \( 5 + 18 + 1 = 24 \) valence electrons.

2. Arrange the atoms:
- Place nitrogen in the center and surround it with three oxygen atoms.

3. Distribute the electrons:
- Start by forming single bonds between nitrogen and each oxygen (3 single bonds use 6 electrons).
- Distribute the remaining electrons to satisfy the octet rule for oxygen atoms.

4. Form a double bond:
- To satisfy the octet rule for nitrogen, one of the oxygen atoms will form a double bond with nitrogen, while the other two will have single bonds and carry a negative charge.

### Step 2: Identify Possible Resonance Structures
1. The first resonance structure can be represented as:
- \( \text{N} \) with a double bond to one \( \text{O} \) (let's say \( \text{O}_1 \)), and single bonds to the other two \( \text{O} \) atoms (\( \text{O}_2 \) and \( \text{O}_3 \)), where \( \text{O}_2 \) and \( \text{O}_3 \) carry negative charges.

2. Shift the double bond to another oxygen:
- In the second resonance structure, \( \text{N} \) will have a double bond with \( \text{O}_2 \) and single bonds with \( \text{O}_1 \) and \( \text{O}_3 \).

3. Shift the double bond to the third oxygen:
- In the third resonance structure, \( \text{N} \) will have a double bond with \( \text{O}_3 \) and single bonds with \( \text{O}_1 \) and \( \text{O}_2 \).

### Step 3: Count the Resonance Structures
- After drawing all possible structures, we find that there are three resonance structures for the nitrate ion.

### Conclusion
The total number of resonance structures that can be drawn for the nitrate ion \( \text{NO}_3^{-} \) is **3**.

---