Resonance structure of a molecule cannot have

Options

A. Identical arrangement of atoms
B. Nearly same energy content
C. The same number of paired electrons
D. Identical bonding

Answer

To determine what a resonance structure of a molecule cannot have, we need to analyze the characteristics of resonance structures. Let's break down the solution step by step:

### Step 1: Understand Resonance
Resonance occurs in molecules where there are multiple valid Lewis structures (resonance structures) that can represent the same molecule. These structures differ only in the arrangement of electrons, not in the arrangement of atoms.

**Hint:** Resonance structures are different ways to represent the same molecule that involve shifting electrons.

### Step 2: Identify Characteristics of Resonance Structures
1. **Identical Arrangement of Atoms:** All resonance structures must have the same arrangement of atoms. This means that the positions of the nuclei remain unchanged.

2. **Similar Energy Content:** Resonance structures should have nearly the same energy. This is because they are representations of the same molecule, and significant energy differences would indicate that one structure is more stable than the other.

3. **Same Number of Paired Electrons:** The total number of paired electrons (bonding and lone pairs) must remain constant across resonance structures. This is because the overall electron count does not change.

4. **Identical Bonding:** This characteristic is not true for resonance structures. While the arrangement of atoms and the number of electrons may remain constant, the type of bonding (single, double, etc.) can change between resonance structures.

**Hint:** Pay attention to how electrons are rearranged in resonance structures, but the atoms themselves do not change positions.

### Step 3: Analyze the Options
- **Option 1:** Identical arrangement of atoms - **True** (resonance structures must have the same atom arrangement).
- **Option 2:** Nearly same energy content - **True** (the energy of resonance structures is similar).
- **Option 3:** Same number of paired electrons - **True** (the total number of paired electrons remains constant).
- **Option 4:** Identical bonding - **False** (the type of bonding can differ between resonance structures).

### Conclusion
The correct answer is that resonance structures cannot have **identical bonding**. This is the characteristic that does not hold true for resonance structures.

**Final Answer:** Resonance structures cannot have identical bonding.