Which of the following set of solids contains only ionic solids ?

Options

A. NaCl, MgO & ZnS
B. `CaF_(2), ZnS, SiO_(2)`
C. `MgO, SiO_(2), KCl`
D. `SiO_(2), SiC, AlN`

Answer

To determine which set of solids contains only ionic solids, we need to analyze each option provided and identify the nature of the bonds in each solid. Ionic solids are characterized by the presence of ionic bonds, which form through the complete transfer of electrons between a metal and a non-metal.

### Step-by-Step Solution:

1. **Identify Ionic Solids**:
- Ionic solids are formed between metals and non-metals due to the transfer of electrons.

2. **Analyze Each Option**:
- **Option 1**: NaCl, MgO, ZnS
- **NaCl**: Sodium (Na) is a metal and Chlorine (Cl) is a non-metal. This forms an ionic bond.
- **MgO**: Magnesium (Mg) is a metal and Oxygen (O) is a non-metal. This also forms an ionic bond.
- **ZnS**: Zinc (Zn) is a metal and Sulfur (S) is a non-metal. This forms an ionic bond as well.
- Conclusion: All three are ionic solids.

- **Option 2**: CaF2, ZnS, SiO2
- **CaF2**: Calcium (Ca) is a metal and Fluorine (F) is a non-metal. This forms an ionic bond.
- **ZnS**: As previously analyzed, this is an ionic solid.
- **SiO2**: Silicon (Si) and Oxygen (O) are both non-metals, forming covalent bonds.
- Conclusion: This set contains a covalent solid (SiO2), so it is not valid.

- **Option 3**: MgO, SiO2, SiC
- **MgO**: This is an ionic solid.
- **SiO2**: This is a covalent solid.
- **SiC**: Silicon (Si) and Carbon (C) are both non-metals, forming covalent bonds.
- Conclusion: This set contains covalent solids, so it is not valid.

- **Option 4**: SiO2, SiC
- **SiO2**: This is a covalent solid.
- **SiC**: This is also a covalent solid.
- Conclusion: Both are covalent solids, so this option is not valid.

3. **Final Conclusion**:
- The only set that contains only ionic solids is **Option 1: NaCl, MgO, ZnS**.

### Answer:
The set of solids that contains only ionic solids is **Option 1: NaCl, MgO, ZnS**.