Structure of Solids, Liquids & Gases
Chemistry: Cambridge International GCSE Supplement, topic 1.1.2
Structure of Solids, Liquids and Gases
Solids, liquids, and gases have different particle arrangements, separations, and motions.
Structure of solids
- Solids have particles closely packed in a fixed, orderly pattern.
- Particles vibrate around fixed positions but do not move freely.
- This arrangement makes solids rigid and keeps a fixed shape and volume.
Structure of liquids
- Liquid particles are close but not in fixed positions, allowing them to move past one another.
- Particles are less orderly than solids and have more space between them.
- Particles move constantly, which lets liquids flow and take the shape of their container.
- Discoveries about liquids advanced in the 19th century with the study of fluid dynamics.
Structure of gases
- Gas particles are far apart and move randomly at high speeds.
- Particles fill any container completely, spreading out evenly.
- Gases have no fixed shape or volume because particles are free to move widely.
Comparison of states
- Solids have tightly packed, fixed particles.
- Liquids have close but mobile particles.
- Gases have widely spaced, fast-moving particles.
- Solids keep shape and volume.
- Liquids keep volume but change shape.
- Gases change both shape and volume.
Particle motion summary
- Particle motion increases from solids to liquids to gases.
- Solids vibrate in place.
- Liquids slide past each other.
- Gases move freely at high speed.
- Particle arrangement and motion explain the properties of each state of matter.
Test yourself on Structure of Solids, Liquids & Gases
How are particles arranged and moving in a liquid?