Paheli asked for a glass of water from Boojho. He gave her a glass of ice cold water. Paheli observed some water droplets on the outer surface of the glass and asked Boojho how these droplets of water were formed? Which of the following should be Boojho’s answer?

Options

A. Evaporation of water from the glass
B. Water that seeped out from the glass.
C. Evaporation of atmospheric water vapour.
D. Condensation of atmospheric water vapour.

Answer

To answer Paheli's question about the water droplets on the outer surface of the glass, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding the Situation**:
- Paheli received a glass of ice-cold water from Boojho.
- She noticed water droplets forming on the outer surface of the glass.

2. **Identifying the Cause**:
- The glass contains ice-cold water, which cools the air around it.
- The temperature of the air (and the water vapor in it) decreases when it comes into contact with the cold surface of the glass.

3. **Explaining Condensation**:
- As the temperature of the water vapor around the glass drops, it reaches a point where it can no longer remain in the gaseous state.
- This process is called condensation, where water vapor changes into liquid water.

4. **Formation of Water Droplets**:
- The condensed water vapor forms tiny droplets on the outer surface of the glass, which is what Paheli observed.

5. **Choosing the Correct Answer**:
- Now, we need to determine which of the provided options correctly explains this phenomenon.
- The correct option is: "Condensation of atmospheric water vapor."

### Conclusion:
Boojho should explain to Paheli that the water droplets on the outer surface of the glass are formed due to the condensation of atmospheric water vapor as the cold surface of the glass cools the air around it.

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