02- Kinetic Particle theory

• What is the kinetic particle theory?

  The Kinetic Particle Theory states that all matter is made up of tiny particles and these particles are in constant random motion
• Properties of solids

  • Particles are very closely packed in an orderly manner
  • The attractive forces between particles is very strong
  • Particles vibrate and rotate about fixed positions, low kinetic energy
  • Cannot be compressed
  • Definite shape
  • Definite volume
• Properties of liquids

  • Particles are packed in a disorderly, random manner
  • The attractive forces between particles is strong
  • Particles slide over each other freely throughout the liquid, low kinetic energy
  • Cannot be compressed
  • No definite shape and follows the shape of containers
  • Definite volume
• Properties of gases

  • Particles are spaced out in a random manner
  • The attractive forces between particles is very weak
  • Particles move rapidly in any direction, high kinetic energy
  • Can be compressed
  • No definite shape
  • No definite volume
• Solid to liquid conversion: Melting

  • The process by which a solid changes to a liquid
  • Melting Point: The temperature at which a solid changes to a liquid
• Liquid to solid conversion: Freezing

  • The process by which a liquid changes to a solid
  • Freezing Point: The temperature at which a liquid changes to a solid
• Liquid to gas conversion: Evaporation, Boiling

  • The process by which a liquid changes to a gas at the boiling temperature of the substance
  • Boiling Point: The temperature at which a liquid boils
  • Evaporation: The process by which a liquid changes to a gas below the boiling point of the substance
• Gas to liquid conversion: Condensation

  • The process by which gas changes into a liquid
• Gas to solid: Deposition

  • gas to solid without the intermediate liquid phase
• solid to gas: sublimation

  • solid to gas without intermediate liquid phase
• Diffusion: process by which particles move freely to fill up any available space, process by which particles move from a region of higher concentration to a region of lower concentration
• Factors affecting rate of diffusion:

  • temperature: more heat energy is converted into kinetic energy of the particles
  • particle mass: particles with higher mass require more energy to move at the same speed
• change in state: when a object is heated, its particles gain energy. they vibrate faster and further. they eventually gain enough energy to overcome the very strong/ strong forces of attraction between them
• expansion: when a substance is heated, its particles gain energy and vibrate more vigorously about their fixed positions, the distance between the particles increase. This causes the volume of the substance to increase

  contaction: when a substance is cooled, its particles lose energy and vibrate less vigorously about their fixed positions, the distance between the particles decrease. This causes the volume of the substance to decrease