Summary:
- Atmospheric pressure is the pressure exerted by gas particles in Earth’s atmosphere as those particles collide with objects.
- A barometer is an instrument used to measure atmospheric pressure.
- At sea level, a mercury column will rise a distance of 760 mm.
- At higher altitudes, the atmospheric pressure is decreased and so the column of mercury will not rise as high.
- On the summit of Mt.
- Everest (elevation of 8848 m), the air pressure is 253 mmHg.
- This marked decrease in atmospheric pressure results in much lower levels of oxygen.