What term is used to denote the amount of water vapour (or moisture) in air?

Options

A. Humidity
B. Weather
C. Climate
D. None of the above

Explanation

**Step-by-Step Solution:**

1. **Understanding the Question**: The question asks for a specific term that refers to the amount of water vapor or moisture present in the air.

2. **Identifying Key Terms**: The key terms in the question are "water vapor," "moisture," and "air." These terms relate to atmospheric conditions.

3. **Defining Water Vapor**: Water vapor is the gaseous form of water and is an invisible component of the atmosphere. It is present in the air in varying amounts.

4. **Exploring Related Terms**: The question provides four options: humidity, weather, climate, and none of the above. We need to determine which of these options specifically refers to the amount of water vapor in the air.

5. **Understanding Humidity**: Humidity is defined as the amount of water vapor present in the air. High humidity indicates a high amount of moisture, while low humidity indicates a low amount of moisture.

6. **Differentiating Weather and Climate**: Weather refers to the short-term atmospheric conditions, including temperature, humidity, and precipitation at a specific time. Climate, on the other hand, refers to the long-term average of weather conditions in a particular region.

7. **Conclusion**: Based on the definitions and understanding of the terms, the correct answer to the question is "humidity," as it specifically denotes the amount of water vapor in the air.

**Final Answer**: The term used to denote the amount of water vapor (or moisture) in air is **humidity**.

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