Solids, Liquids & Gases (Edexcel IGCSE Physics)

• There are three different states of matter: solid, liquid, or gas

Solid state of matter

• In a solid state of matter:
  • The particles are closely packed
  • The particles vibrate about fixed positions

• Solids have:
  • A definite shape (they are rigid)
  • A definite volume

Liquid state of matter

• In a liquid state of matter:
  • The particles are closely packed
  • The particles can flow over one another

• Liquids have:
  • No definite shape – they are able to flow and will take the shape of a container
  • A definite volume

Gas state of matter

• In a gas state of matter:
  • The particles are far apart
  • The particles move randomly

• Gases have:
  • No definite shape – they will take the shape of their container
  • No fixed volume – if placed in an evacuated container they will expand to fill the container

• Gases are highly compressible, this is because:
  • There are large gaps between the particles
  • It is easier to push the particles closer together than in solids or liquids

The three states of matter

Diagram showing the three states of matter in terms of shape and volume

Properties of states of matter

State	Solid	Liquid	Gas
Density	High	Medium	Low
Arrangement of particles	Regular pattern	Randomly arranged	Randomly arranged
Movement of particles	Vibrate around a fixed position	Move around each other	Move quickly in all directions
Energy of particles	Low energy	Greater energy	Highest energy