Sample Cheat Sheets: Solid, Liquids and Gases
1.1 Solids, Liquids and Gases – Cheat Sheet
| State of Matter | Particle Separation | Arrangement | Motion | Shape | Volume | Compressibility | Example |
|---|---|---|---|---|---|---|---|
| Solid | Very close | Fixed, regular | Vibrate about fixed positions | Fixed | Fixed | Very low | Ice |
| Liquid | Close | Random | Slide past each other | Takes shape of container | Fixed | Low | Water |
| Gas | Far apart | Random | Rapid, free movement | Fills container | Not fixed | High | Oxygen |
Kinetic Particle Theory (KPT) Descriptions
- Solids: Strong forces of attraction, fixed lattice, particles vibrate only
- Liquids: Weaker forces than solids, particles can move and slide, still close together
- Gases: Negligible forces, particles far apart, moving rapidly in all directions
Changes of State (KPT explanation)
| Change | Description | Particle Behaviour |
|---|---|---|
| Melting | Solid → Liquid | Particles gain kinetic energy, vibrations increase until forces break partially |
| Boiling | Liquid → Gas (throughout) | Particles gain enough kinetic energy to break free completely |
| Evaporating | Liquid → Gas (surface only) | High-energy particles escape from surface |
| Freezing | Liquid → Solid | Particles lose kinetic energy, forces hold them in fixed positions |
| Condensing | Gas → Liquid | Particles lose kinetic energy, move closer together, forces form |
Heating & Cooling Curves
- Flat sections → Change of state, temperature constant while energy is used to break/form forces
- Sloped sections → Temperature changes, kinetic energy changes
- Melting point and boiling point are fixed for pure substances
Gas Behaviour: Effect of Temperature & Pressure (KPT)
- Temperature ↑ → Kinetic energy ↑ → Particles move faster → Volume ↑ (if pressure constant)
- Pressure ↑ (at constant temperature) → Volume ↓ because particles are forced closer together
- Boyle’s Law: P₁V₁ = P₂V₂ (at constant temperature)
- Charles’s Law: V/T = constant (at constant pressure)
Example Questions for Quick Recall
- Why can gases be compressed easily? → Large spaces between particles
- Why does evaporation cause cooling? → Fastest particles escape, average kinetic energy decreases
- Why is boiling point higher for a substance with stronger intermolecular forces? → More energy needed to separate particles
Written and Compiled By Sir Hunain Zia, World Record Holder With 154 Total A Grades, 7 Distinctions and 11 World Records For Educate A Change O Level And IGCSE Chemistry Full Scale Course
Common Examples & Applications
| Process | Example |
|---|---|
| Melting | Ice to water |
| Boiling | Water to steam |
| Evaporation | Clothes drying |
| Freezing | Water to ice |
| Condensation | Water droplets on cold glass |
Particle Diagrams (Representation)
- Solid: ●●● in fixed rows, tightly packed
- Liquid: ●●● close but random, some gaps
- Gas: ● ● ● widely spaced, random
Exam Tip Table – Distinguishing Properties
| Property | Solid | Liquid | Gas |
|---|---|---|---|
| Shape | Fixed | Not fixed | Not fixed |
| Volume | Fixed | Fixed | Not fixed |
| Flow | No | Yes | Yes |
| Density | High | High | Low |
Written and Compiled By Sir Hunain Zia, World Record Holder With 154 Total A Grades, 7 Distinctions and 11 World Records For Educate A Change O Level And IGCSE Chemistry Full Scale Course