Which of the following is the incorrect match ?

Options

A. Molecular solid (polar) : Dry Ice
B. Ionic solid : `CaF_(2)`
C. Metallic solid : Ag
D. Network solid : `SiO_(2)`

Answer

To determine which of the following is the incorrect match, we need to analyze each option provided:

1. **Molecular Solid - Dry Ice (Solid Carbon Dioxide)**
2. **Ionic Solid - Calcium Fluoride**
3. **Metallic Solid - Silver**
4. **Network Solid - Silicon Dioxide**

### Step-by-Step Solution:

**Step 1: Analyze Dry Ice (Solid Carbon Dioxide)**
- Dry ice is indeed solid carbon dioxide (CO₂).
- CO₂ has polar bonds (C=O), but the molecule is linear, leading to the cancellation of dipole moments.
- Therefore, CO₂ is a non-polar molecule in its solid state.
- This means that labeling dry ice as a molecular solid with polar characteristics is incorrect.

**Step 2: Analyze Calcium Fluoride**
- Calcium fluoride (CaF₂) is composed of calcium ions (Ca²⁺) and fluoride ions (F⁻).
- It forms a crystal lattice structure typical of ionic solids.
- This match is correct.

**Step 3: Analyze Silver**
- Silver (Ag) is a metal and exhibits metallic bonding.
- It is classified as a metallic solid.
- This match is correct.

**Step 4: Analyze Silicon Dioxide**
- Silicon dioxide (SiO₂) has a network structure where each silicon atom is covalently bonded to four oxygen atoms, forming a strong three-dimensional network.
- This structure is characteristic of network solids.
- This match is correct.

### Conclusion:
The incorrect match is the first option: **Molecular Solid - Dry Ice (Solid Carbon Dioxide)**, as dry ice is a non-polar molecular solid, not a polar one.

### Final Answer:
**The incorrect match is: Molecular Solid - Dry Ice (Solid Carbon Dioxide)**

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