Three States Matter

• Solids


  • Extremely hard to compress
  • Fixed shape, cannot flow
• Particles in solids


  Packed together in a regular pattern with almost no spaces between them
• Liquids


  • Extremely hard to compress
  • Take the shape of their container, can flow
• Particles in liquids


  Close together with not many spaces, can move
• Gases


  • Extremely easy to compress
  • Spread out and fill the space of their container
• Particles in gases


  Widely spaced, move quickly and randomly
• Melting


  1. Heating a solid to change it to a liquid

  2. Takes place at the melting point
• Particles in a liquid

  Have more kinetic energy than in a solid
• Energy is needed to break the forces of attraction between particles in a solid to change it to a liquid
• Stronger the forces of attraction between particles

  Higher the melting point
• Solids with different melting points

  • Wax candle (relatively low)
  • Sodium chloride (very high)
• Freezing


  1. Cooling a liquid to change it to a solid

  2. Takes place at the melting point
• Boiling


  1. Heating a liquid to change it to a gas

  2. Takes place at the boiling point
• Strong forces of attraction between particles require more energy to break and result in a higher boiling point
• Condensing


  1. Cooling a gas to change it to a liquid

  2. Takes place at the boiling point
• Limitations of simple particle model

  • Assumes particles are solid spheres
  • Assumes no forces between particles
• The forces of attraction between particles have a major impact on the melting and boiling points of a substance