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 matches is incorrect, we will analyze each option provided in the question regarding the types of solids and their characteristics.

### Step-by-Step Solution:

1. **Identify the Types of Solids**:
- We have four types of solids to consider: molecular solids, ionic solids, metallic solids, and network (covalent) solids.

2. **Analyze the First Option**:
- **Molecular Solids - Polar and Dry Ice**:
- Dry ice is solid CO2. CO2 is a linear molecule with a symmetrical arrangement of atoms, leading to a net dipole moment of zero. Therefore, CO2 is classified as a non-polar molecule. Hence, the match of "molecular solids" with "polar" is incorrect because dry ice is non-polar.

3. **Analyze the Second Option**:
- **Ionic Solids - CaF2**:
- Calcium fluoride (CaF2) is an ionic compound. It consists of Ca²⁺ cations and F⁻ anions held together by strong electrostatic forces. This match is correct.

4. **Analyze the Third Option**:
- **Metallic Solids - Silver**:
- Silver (Ag) is a metal and exhibits metallic bonding, characterized by a sea of delocalized electrons around positively charged metal ions. This match is also correct.

5. **Analyze the Fourth Option**:
- **Network Solids - SiO2 (Quartz)**:
- Silicon dioxide (SiO2) forms a network solid where each silicon atom is covalently bonded to four oxygen atoms, creating a three-dimensional structure. This match is correct.

6. **Conclusion**:
- The only incorrect match is the first one: "Molecular Solids - Polar and Dry Ice". Therefore, the answer is that the incorrect match is option A.

### Final Answer:
The incorrect match is: **A - Molecular Solids - Polar and Dry Ice**.