Density

• Solids


  • Particles are very close together and arranged in a regular pattern
  • Particles vibrate but do not move from place to place
• Liquids


  • Particles are still close together but not arranged in a regular pattern
  • Particles can move around each other
• Gases


  • Particles are very far apart and not arranged in any pattern
  • Particles are moving very rapidly
• Density


  The mass of a material for a given volume
• High density materials


  • Brick
  • Liquid
• Low density materials


  • Polystyrene block
• Solids usually have high density because particles are packed closely together
• Liquids usually have high density because particles are close together
• Gases have low density because particles are far apart
• Polystyrene is a solid with low density due to its open structure and air spaces