Physical properties of solids, liquids and gases

Curriculum check:    ✓ Edexcel IGCSE      ✓ OCR GCSE


How solids, liquids and gases behave…

Solids:

Solids are made of very tightly-packed particles with strong bonds/attractive forces between them – this means they …

  • …are very difficult to compress (incompressible) – there’s not much room to push them closer together …
  •  cannot flow 
  • …so they keep their shape – the attractive forces between the tightly-packed particles are so strong that they are very difficult to break.

Liquids:

Liquids are made of closely-packed particles with weak bonds/attractive forces between them – this means they …

  • …are difficult to compress (incompressible) – there’s more room between the particles than in solids, but not enough to be pushed closer together …
  • … but can flow  –  it’s easy for the particles to move past each other …
  • …so they take the shape of the bottom of the container.

Gases:

Gases are made of particles that are very far apart with practically zero bonds/attractive forces between them – this means they …

  • …are easy to compress (compressible) – there’s loads of space to push the particles closer together …
  • … and like liquids, they can flow  –  it’s easy for the particles to move past each other … (both liquids and gases are called FLUIDS because they can flow)
  • …so they fill the entire container.