* Boiling Point: The temperature at which a liquid's vapor pressure equals the surrounding atmospheric pressure, causing the liquid to turn into a gas.
* Atmospheric Pressure: The weight of the air above a particular location.
How it works:
1. Air Pressure and Elevation: As you go higher in elevation, there is less air above you, leading to a decrease in atmospheric pressure.
2. Vapor Pressure: The pressure exerted by the vapor of a liquid above its surface. This pressure increases as the liquid heats up.
3. Equilibrium: At the boiling point, the vapor pressure of the liquid equals the atmospheric pressure.
4. Lower Pressure, Lower Boiling Point: Since atmospheric pressure is lower at higher elevations, the liquid needs less vapor pressure to reach equilibrium. This means the liquid will boil at a lower temperature.
Example:
Water boils at 100°C (212°F) at sea level, where the atmospheric pressure is about 1 atmosphere (atm). However, at a higher elevation like Mount Everest, the atmospheric pressure is much lower, and water will boil at around 68°C (154°F).
Important Note: This decrease in boiling point is significant for cooking at higher elevations, as food takes longer to cook due to the lower boiling temperature of water.
