Which state of matter has a definite shape and volume?

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

Answer: (D)

Definite shape and volume come from how tightly the particles are arranged and how little they move. In a solid, particles are packed tightly in fixed positions and mainly vibrate in place. That strong, organized structure gives the material its own rigid shape and a set amount of space, so both its shape and its volume stay constant.

Liquids have a definite volume because their particles are close together, but they can slide past one another, so they flow and take the shape of their container rather than keeping a fixed shape. Gases spread out to fill whatever space is available and can be compressed, so they don’t have a fixed shape or a fixed volume. Plasma is a high-energy state where particles are ionized; under many conditions it behaves like a gas and does not have a definite shape or volume.

So, the state with a definite shape and volume is the solid.