Understanding Gas Pressure and Atmospheric Pressure

Existence of Gas Pressure.

1) According to the Kinetic Theory Of Gases, molecules in a gas are always moving randomly and constantly colliding with the wall of its container.
2) Collisions of gas molecules with the walls of the container occur frequently, resulting in a change of momentum which exerts a force on the wall of the container.


Existence of Atmospheric Pressure.

1) The atmosphere is the layer of mixture of gases such an nitrogen, oxygen and carbon dioxide that surrounds the Earth.
2) The weight of this mass of the atmosphere exerts pressure on the surface is called atmosphere pressure.