Air, helium and chlorine are gases at room temperature. Water vapour is water as a gas. The particles in a gas are:
The particles in a gas can:
The attractive forces between the particles in a gas are very weak, so the particles are free to move in any direction.
The table shows some of the properties of gases and why they are like this:
|They flow and completely fill their container||The particles can move quickly in all directions|
|They can be compressed (squashed)||The particles are far apart and have space to move into|