Particle motion
The A general term for a small piece of matter. For example, protons, neutrons, electrons, atoms, ions or molecules. in a gas move very quickly in random directions. Collisions frequently happen between:
- particles
- particles and the wall of the container
The effect of collisions with the container is to produce a net A push or a pull. The unit of force is the newton (N). acting on the container walls. This force acts at right angles to the container walls, which is detected as gas Force exerted over an area. The greater the pressure, the greater the force exerted over the same area.. This pressure can be measured using a pressure gauge.
For example, the collisions caused by a gas trapped inside a balloon cause forces to act outwards in all directions, giving the balloon its shape.
The pressure caused by a gas can be calculated using the equation:
\(pressure = \frac{force}{area}\)
This is when:
- pressure is measured in newtons per metre squared (N/m²)
- force is measured in newtons (N)
- Area is the measurement of the amount of space inside a surface. is measured in metres squared (m²)
Another unit of pressure is the Unit of pressure. Pascal (Pa), eg normal atmospheric pressure is 1.01x105 Pa. (Pa):
- 1 Pa = 1 N/m2
- 1 kPa = 1,000 Pa
A A reaction vessel where no reactants or products can escape or are lost to the surroundings. is a system where no substances can enter or leave, such as a balloon filled with air and tied off, or a A moving component of a machine that is contained by a cylinder and is made gas-tight by piston rings.. A gas in a closed system can be:
- Made smaller by squeezing together. by reducing its The volume of a three-dimensional shape is a measure of the amount of space or capacity it occupies, eg an average can of fizzy drink has a volume of 330 ml., which increases its pressure
- expanded by increasing its volume, which decreases its pressure.