To determine which of the given options is not a permissible resonating form, we need to analyze each option based on the rules of resonance, particularly focusing on the stability of charges and the octet rule.
### Step-by-Step Solution:
1. **Understand the Concept of Resonance:**
- Resonance structures are different ways of drawing the same molecule that differ only in the placement of electrons. The most stable resonance forms are those that satisfy the octet rule and place charges on the appropriate atoms based on their electronegativity.
2. **Evaluate Each Option:**
- For each option, we will check the placement of charges and whether the octet rule is satisfied.
3. **Option 1:**
- Analyze the structure: Check if the positive charge is on a less electronegative atom (like carbon) and if the octet rule is satisfied for nitrogen.
- Conclusion: This is a permissible resonating form.
4. **Option 2:**
- Analyze the structure: Check the placement of the positive charge on nitrogen and the negative charge on oxygen. Oxygen is more electronegative, which is favorable.
- Conclusion: This is also a permissible resonating form.
5. **Option 3:**
- Analyze the structure: Here, nitrogen has a positive charge and is shown to accommodate 10 electrons (1, 2, 3, 4, 5, 6, 7, 8, 9, 10).
- Conclusion: Nitrogen, being a second-period element, cannot accommodate more than 8 electrons due to the absence of vacant orbitals. Therefore, this is **not a permissible resonating form**.
6. **Option 4:**
- Analyze the structure: Negative charge on carbon and positive charge on nitrogen. Check if the octet rule is satisfied for nitrogen.
- Conclusion: The octet for nitrogen is satisfied (1, 2, 3, 4, 5, 6, 7, 8). This is a permissible resonating form.
7. **Final Answer:**
- The option that is not a permissible resonating form is **Option 3**.
