In high altitudes, the boiling point of water decreases because

Options

A. the atmospheric pressure is high
B. the temperature is low
C. the atmospheric pressure is low
D. the temperature is high.

Answer

**Step-by-Step Solution:**

1. **Understanding Boiling Point:** The boiling point of a liquid is the temperature at which its vapor pressure equals the surrounding atmospheric pressure. At this point, the liquid turns into vapor.

2. **Effect of Atmospheric Pressure:** At sea level, the atmospheric pressure is about 101.3 kPa (kilopascals). As you ascend to higher altitudes, the atmospheric pressure decreases.

3. **High Altitude Conditions:** In high altitudes, the air pressure is significantly lower than at sea level. For example, at 3,000 meters above sea level, the atmospheric pressure can drop to about 70 kPa.

4. **Relation to Boiling Point:** Since the boiling point is dependent on atmospheric pressure, when the pressure decreases, the temperature at which water boils also decreases. This means that water will boil at a lower temperature in high altitudes compared to sea level.

5. **Conclusion:** Therefore, the boiling point of water decreases at high altitudes because the atmospheric pressure is lower.

**Final Answer:** In high altitudes, the boiling point of water decreases because the atmospheric pressure is low.

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