Final answer:
Solids have a definite shape and fixed volume, while liquids and gases do not have a definite shape. Gases have no fixed volume, while liquids have a fixed volume.
Step-by-step explanation:
Solids have a definite shape and fixed volume. They do not change their shape or volume when placed in a different container. Liquids, on the other hand, have a definite volume but take the shape of the container they are in. Gases have neither a definite shape nor a fixed volume, as they completely fill their container regardless of volume.