Atmospheric Pressure

This lesson covers:

  1. What 'atmospheric pressure' is
  2. What generates atmospheric pressure 

Which of the following is not a gas in the atmosphere?

Carbon dioxide

Nitrogen

Carbon

Oxygen

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Atmospheric pressure is _________ at a higher elevation.

lower

higher

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Illustration of gas particles moving in random directions and colliding with each other.

The atmosphere on earth is made up of countless gas particles, all flying about in random directions.

Illustration of a gas particle exerting a tiny force on a cubic object.

Every time a gas particle collides with anything (including other gas particles), it exerts a tiny force on the thing it hits.


Illustration showing gas particles colliding with a cube representing atmospheric pressure.

In reality, this means any object on earth is being constantly hit, from all sides, by an huge number of tiny forces.


This is what 'atmospheric pressure' refers to - the total force of all the air particles constantly colliding with everything, from all sides.

There is greater atmospheric pressure at sea level than at higher elevation. Why is this?

(Select all that apply)

The air is more dense at sea level

There are more gas particles at sea level to collide with objects

The air is less dense at sea level

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The two main gases which make up the atmosphere are n and o.

itrogen
xygen

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