Which state of matter has no definite shape and no definite volume?

• A. Plasma
• B. Solid
• C. Liquid
• D. Gas

Answer: (D)

In gases, particles are far apart and move rapidly, so they don’t hold a fixed shape or a fixed volume. They spread to fill whatever container they’re in and can be compressed, so neither the shape nor the amount of space they occupy is fixed. By contrast, solids keep a definite shape and volume because their particles are tightly packed, and liquids hold a definite volume but take the shape of their container because their particles flow and slide past each other. For these reasons, gas is the state with no definite shape and no definite volume.