Cambridge IGCSE Chemistry: Chapter 1 - States of Matter Study Notes

What is Matter?: Anything with mass and volume.

Three States of Matter:

• Solid:

• Fixed shape and volume.

• High density.

• Does not flow.

• Liquid:

• Fixed volume, changes shape.

• Moderate to high density.

• Flows easily.

• Gas:

• No fixed shape or volume; expands to fill container.

• Low density.

• Flows easily.

Fluid: Liquids and gases that can flow.   

Expansion/Contraction: All states expand with heat and contract with cold.

Compressibility:

• Gases: Can be compressed.

• Liquids: Slightly compressible.

• Solids: Not compressible.

Physical State Changes:

• Melting: Solid to liquid.

• Freezing: Liquid to solid.

• Evaporation: Liquid to gas on the surface.

• Boiling: Liquid changes to gas throughout.

• Condensation: Gas to liquid.

• Sublimation: Solid to gas (skip liquid phase).

Melting Point (m.p.): Temperature at which a solid becomes a liquid.

Boiling Point (b.p.): Temperature at which a liquid boils.

Pure Substances: Have consistent m.p. and b.p. (e.g., water: m.p. 0°C, b.p. 100°C).

Mixtures: Two or more substances that can be physically separated.

• Solution: A type of mixture where a solute dissolves in a solvent.

Diffusion: Mixing of particles from high to low concentration.

Key Experiments:

• Bromine gas spreading after evaporation.

• Smoke rings from ammonia and hydrochloric acid reaction.