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 will analyze each option provided:

### Step-by-Step Solution:

1. **Analyze Option 1: NaCl, MgO, ZnS**
- **NaCl (Sodium Chloride)**: This is an ionic compound formed from sodium ions (Na⁺) and chloride ions (Cl⁻).
- **MgO (Magnesium Oxide)**: This is also an ionic compound formed from magnesium ions (Mg²⁺) and oxide ions (O²⁻).
- **ZnS (Zinc Sulfide)**: This compound is ionic as well, formed from zinc ions (Zn²⁺) and sulfide ions (S²⁻).
- **Conclusion**: All three compounds in this option are ionic.

2. **Analyze Option 2: CaF2, ZnS, SiO2**
- **CaF2 (Calcium Fluoride)**: This is an ionic compound formed from calcium ions (Ca²⁺) and fluoride ions (F⁻).
- **ZnS (Zinc Sulfide)**: As established earlier, this is ionic.
- **SiO2 (Silicon Dioxide)**: This is a covalent compound, not ionic.
- **Conclusion**: This option contains a covalent compound (SiO2), so it does not consist only of ionic solids.

3. **Analyze Option 3: MgO, SiO2, KCl**
- **MgO (Magnesium Oxide)**: Ionic.
- **SiO2 (Silicon Dioxide)**: Covalent.
- **KCl (Potassium Chloride)**: Ionic.
- **Conclusion**: This option contains a covalent compound (SiO2), so it does not consist only of ionic solids.

4. **Analyze Option 4: SiO2, SiC, AlN**
- **SiO2 (Silicon Dioxide)**: Covalent.
- **SiC (Silicon Carbide)**: Covalent.
- **AlN (Aluminum Nitride)**: This is primarily covalent in character.
- **Conclusion**: All three compounds in this option are covalent, so it does not consist only of ionic solids.

### Final Conclusion:
The only option that contains only ionic solids is **Option 1: NaCl, MgO, ZnS**.