In other words, gases neither have a definite shape nor a definite volume. They occupy the full volume of the container they are in. Their shape is also that of the container.

The table alongside lists whether solids, liquids and gases have a definite shape or definite volume.
When you buy milk from the market, you can ask for 1 litre of milk. Imagine milk was in a gaseous form. Would it then be useful to sell 1 litre of gaseous milk?
  • Yes
  • No