## Do gas particles repel each other?

Gas particles are hard spheres with no internal structure. The volume of the spheres is negligible in comparison to the average distance between particles. The gas particles neither attract or repel one another (they possess no potential energy).

## What happens to the particles in a gas when it is compressed?

When more gas particles enter a container, there is less space for the particles to spread out, and they become compressed. The particles exert more force on the interior volume of the container. This force is called pressure. There are several units used to express pressure.

## Are gas particle collisions elastic?

Collisions between gas particles and between particles and the container walls are elastic collisions. There are no forces of attraction or repulsion between gas particles. The average kinetic energy of gas particles is dependent upon the temperature of the gas.

## Does pressure depend on mass of particles?

T is the temperature of the gas. Therefore, the mass of the gas is proportional to the number of moles of the gas, which is, in turn, proportional to the pressure. Therefore, the pressure is proportional to the mass of the gas, meaning that, yes, the pressure of the gas does depend on its mass.

Boyle’s law states that at constant temperature the volume of a given mass of a dry gas is inversely proportional to its pressure.

## What forces are considered when fluid is at rest?

In addition to gravity, a fluid in motion will have surface forces due to viscous stresses. Viscous forces, however, for a fluid at rest are zero.

## Why does pressure decrease with height?

As altitude increases, the amount of gas molecules in the air decreasesâ€”the air becomes less dense than air nearer to sea level. This is what meteorologists and mountaineers mean by “thin air.” Thin air exerts less pressure than air at a lower altitude.

## What does atmospheric pressure mean?

That pressure is called atmospheric pressure, or air pressure. It is the force exerted on a surface by the air above it as gravity pulls it to Earth. Atmospheric pressure is commonly measured with a barometer. Atmospheric pressure drops as altitude increases.