Key Concepts: States of Matter

The Three States of Matter

• Solid: Particles are tightly packed in a fixed structure. They vibrate in place but do not move freely. Solids have a definite shape and volume.
• Liquid: Particles are close together but can move past one another. Liquids have a definite volume but take the shape of their container.
• Gas: Particles are far apart and move freely at high speeds. Gases have no definite shape or volume and will expand to fill their container.