Solids with Schottky defects are electrical insulators.

Explanation

To determine whether solids with Schottky defects are electrical insulators, we can analyze the nature of Schottky defects and their implications on electrical conductivity.

### Step-by-Step Solution:

1. **Understanding Schottky Defects**:
- Schottky defects occur in ionic solids where equal numbers of cations and anions are missing from the lattice structure. This results in vacancies in the crystal.

2. **Charge Neutrality**:
- Since the number of missing cations equals the number of missing anions, the overall charge of the solid remains neutral. This is a key characteristic of Schottky defects.

3. **Examples of Solids with Schottky Defects**:
- Common examples of ionic solids that exhibit Schottky defects include sodium chloride (NaCl) and potassium chloride (KCl).

4. **Electrical Conductivity**:
- For a material to conduct electricity, it must have charged particles (ions or electrons) that are free to move. In the case of solids with Schottky defects, the missing ions create vacancies, but these vacancies do not contribute to the conduction of electricity because there are no extra charges available to carry the current.

5. **Conclusion**:
- Since Schottky defects do not introduce any extra charge carriers and maintain electrical neutrality, solids with Schottky defects behave as electrical insulators.

### Final Statement:
Thus, it can be concluded that solids with Schottky defects are indeed electrical insulators due to the absence of free charge carriers.

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