Which state of matter has neither a fixed shape nor a fixed volume?

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

Answer: (C)

Matter can exist in different states based on how their particles move and how closely they’re held together. In a solid, particles are tightly packed and vibrate in place, giving it a definite shape and volume. In a liquid, particles can slide past each other, so it has a definite volume but takes the shape of its container. In a gas, particles are far apart and move freely, so they spread to fill whatever space is available, giving no fixed shape and no fixed volume. Plasma behaves similarly to a high-energy gas, but in basic contexts gas is the standard example for this property. So, the state that has neither a fixed shape nor a fixed volume is gas.