Science Revision

• Solid


  • Fixed volume
  • Changes shape
  • Cannot be compressed
  • Does not flow
  • High density
• Liquid


  • Fixed volume
  • Changes shape
  • Cannot be compressed
  • Flows easily
  • Low density
• Gas


  • Changes shape
  • Can be compressed
  • Flows easily
  • Low density
• Solid


  • Wood
  • Metal
  • Stone
  • Plastic
• Liquid


  • Water
  • Oil
  • Solutions
• Gas


  • Air
  • Smoke
  • Steam
• Phase changes


  1. Melting

  2. Freezing

  3. Evaporating

  4. Condensing

  5. Sublimation
• Solids cannot be compressed because the space between the particles is too small
• Gases can be compressed because the particles are more spread out
• Liquids can flow because the particles are not fixed in position
• Solids cannot flow because the particles are in a fixed lattice
• Increased temperature


  Causes particles to gain energy, vibrate more, and bonds to break, turning solid to liquid (melting)
• A drop of ink spreads out evenly through water
• Diffusion


  The process of a drop of ink spreading out evenly through water
• Mixture


  Contains substances that are not chemically bonded
• Compound


  Contains only one type of element
• Mixtures can contain solids, liquids, or gases
• Compounds can be separated easily
• Solid


  • Smoke
• Liquid


  • Solutions (e.g. salt water)
  • Aerosols and foams
  • Beer
• Gas


  • Air
• Filtration


  A separation technique where an insoluble solid is separated from a liquid
• Solvent


  The substance which something dissolves in
• Solute


  The substance which is dissolved
• Separating pure salt from rock salt

  1. Mix with water

  2. Filter to separate rock/sand from salt water

  3. Evaporate water to leave salt crystals
• Chromatography


  A separation technique used to separate the different dyes in ink