Which of the following substance is used in refrigerators?

Options

A. hydrocarbon
B. CFC
C. ozone
D. metal oxide

Explanation

**Step-by-Step Solution:**

1. **Understanding the Question:** The question asks which substance is used in refrigerators.

2. **Identifying Common Refrigerants:** Refrigerators use specific substances known as refrigerants. Common refrigerants include chlorofluorocarbons (CFCs), hydrocarbons, ammonia, and others.

3. **Analyzing the Options:**
- **Hydrocarbon:** Generally not used in traditional refrigerators due to flammability.
- **CFC (Chlorofluorocarbon):** This is a well-known refrigerant that is non-flammable, tasteless, and odorless. It is chemically stable and has a boiling point close to 0°C, making it ideal for refrigeration.
- **Ozone (O3):** This is not used as a refrigerant; it is a molecule found in the atmosphere.
- **Metal Oxide:** This is not a refrigerant and is not used in refrigerators.

4. **Conclusion:** Based on the properties and the analysis of the options, the correct answer is CFC (Chlorofluorocarbon).

5. **Final Answer:** The substance used in refrigerators is **CFC (Chlorofluorocarbon)**.

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