3.1.2 Solids, Liquids & Gases

• Three States of Matter

  • Solids
  • Liquids
  • Gases
• Solids

  • Fixed shape and volume
  • High density
  • Incompressibility
  • Low energy
• Liquids

  • Variable shape but fixed volume
  • Medium density
  • Slight compressibility
  • Medium energy
• Gases

  • Variable shape and volume
  • Low density
  • Highly compressible
  • High energy
• Particle Arrangement in Solids

  Particles are arranged in a regular, fixed pattern
• Particle Arrangement in Liquids

  Particles are close together but not in a fixed pattern
• Particle Arrangement in Gases

  Particles are far apart with no regular arrangement
• Movement in Solids

  Particles vibrate in place but do not move from their positions
• Movement in Liquids

  Particles move around each other, allowing liquids to flow
• Movement in Gases

  Particles move rapidly and randomly in all directions
• Melting (Solid to Liquid)

  1. Particles gain energy

  2. Vibrate more vigorously

  3. Overcome forces holding them in place
• Freezing (Liquid to Solid)

  1. Particles lose energy

  2. Move more slowly

  3. Settle into a fixed arrangement
• Boiling/Evaporation (Liquid to Gas)

  1. Particles gain energy

  2. Move faster

  3. Break forces of attraction
• Condensation (Gas to Liquid)

  1. Particles lose energy

  2. Move more slowly

  3. Come closer together
• Sublimation (Solid to Gas)

  1. Particles gain energy

  2. Break free from fixed positions

  3. Spread out as a gas
• Heating Curve


  A graph that shows the temperature of a substance as it is heated over time
• Cooling Curve

  A graph that shows the temperature of a substance as it cools over time
• Flat Sections in Heating Curve

  Indicate a change of state where temperature remains constant
• Flat Sections in Cooling Curve

  Indicate a change of state where temperature remains constant
• Particle Model of Matter

  Explains the properties of solids, liquids, and gases based on particle arrangement and movement
• Kinetic Theory

  Describes how the energy of particles relates to temperature and phase changes
• Kinetic Energy in States

  • Solids: Low kinetic energy
  • Liquids: Medium kinetic energy
  • Gases: High kinetic energy
• Density and States of Matter

  • Solids: Highest density
  • Liquids: Lower density than solids but higher than gases
  • Gases: Lowest density
• Changes of State occur when substances gain or lose energy, leading to changes in the arrangement and movement of particles
• Kinetic Theory explains the behavior of particles in different states and how energy changes during phase transitions
• Understanding the differences between solids, liquids, and gases, along with the processes involved in changing states, is fundamental in explaining a wide range of physical phenomena