States of Matter

• Particles have more energy at higher temperatures than at lower temperatures.
• Increasing temperature increases the average speed of particles, leading to increased collisions between them.
• The kinetic theory explains why gases expand when heated and contract when cooled.
• When gas is cooled down, it loses some of its heat energy, resulting in slower particle movement and contraction.
• Gas molecules move faster as they gain heat energy, causing an increase in volume or expansion.
• When gas is cooled down, it loses its heat energy, resulting in slower particle movement and contraction.
• As the temperature rises, the volume of the container expands due to the increase in molecular motion.
• Gas molecules move faster as they gain thermal energy from their surroundings.
• As the temperature decreases, the particles slow down and lose their random motion, resulting in contraction.
• Solids are materials that can be compressed but not easily deformed.
• Liquids are fluids that take on the shape of their container but maintain a constant volume.
• Examples of solids include metals, rocks, and glass.
• Liquid is a state of matter where particles are close together and constantly moving around one another.
• At high temperatures, the particles have enough energy to overcome intermolecular forces and escape from the liquid state into the gaseous state.
• Melting point


  The temperature at which a solid changes completely to a liquid when heat is added
• Just before condensation


  • Articles move more slowly
  • They are no longer far apart
  • Collisions are less intense
• State changes

  • Condensation
  • Freezing
  • Melting
  • Boiling
• Change of state


  A physical change in which a substance changes from one state of matter to another
• Just before freezing


  • Particles move extremely slowly
  • There are only vibrations
  • Particles are very close together
• Freezing point


  The temperature at which a liquid changes completely into a solid when heat is removed
• Boiling point

  The temperature of a liquid at which the vapour pressure is equal to the atmospheric pressure of the surroundings