Question

Why do gases exert pressure?

Answer 1

Gases exert pressure through the collisions of gas molecules with surfaces; this pressure is evident in both Earth's atmosphere and in contained samples like balloons, and can be measured using barometers or manometers.

Step-by-step explanation:

Gases exert pressure due to the force exerted by gas molecules when they collide with the surfaces of objects. Earth's atmosphere is a clear example of this phenomenon, exerting pressure due to gravity acting on the myriad of gas particles present in the atmosphere.

A small sample of gas, such as the gas inside a balloon, also exerts pressure through similar collisions of gas particles with the balloon's inner walls, keeping the balloon inflated. This pressure can be measured and expressed in units such as the pascal, atmosphere, or bar, using devices like barometers or manometers.

Answer 2

Image result for why do gases exert pressure
The molecules are continually colliding with each other and with the walls of the container. When a molecule collides with the wall, they exert small force on the wall The pressure exerted by the gas is due to the sum of all these collision forces.The more particles that hit the walls, the higher the pressure.