* Gases take the shape of their container. Unlike solids, which maintain a fixed shape, and liquids, which take the shape of the bottom of their container, gases expand to fill the entire volume they occupy.
* Gases are compressible. This means you can squeeze them into a smaller space, unlike solids and liquids.
* Gas molecules are far apart and move freely. The particles in a gas have a lot of space between them and move rapidly in random directions. This gives gases their ability to expand and fill a container.
Therefore, gases don't have a fixed shape or volume like solids and liquids do. They are constantly changing and adapting to their environment.
