Why dry air is heavier than moist air?

Explanation

To understand why dry air is heavier than moist air, we can break down the explanation into several steps:

### Step 1: Composition of Dry Air and Moist Air
- **Dry Air**: The primary components of dry air are nitrogen (N₂) and oxygen (O₂). The average molecular masses of these gases are:
- Nitrogen (N₂): 28 g/mol
- Oxygen (O₂): 32 g/mol
- **Moist Air**: Moist air contains the same components as dry air but also includes water vapor (H₂O). The molecular mass of water is:
- Water (H₂O): 18 g/mol
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