Particle and Kinetic Theory

• What are the three states of matter discussed in the video?

  Solid, liquid, and gas
• What model is used to explain how particles behave in different states of matter?

  Particle theory or kinetic theory
• How are particles in solids described in the particle theory?

  As small solid inelastic spheres
• What holds the particles in a solid close together?

  Strong forces of attraction
• What structure do particles in solids form?

  A regular lattice structure
• Why do solids have a definite shape and volume?


  Because the particles are fixed in position
• How do particles in solids behave?

  They vibrate around in fixed positions
• What happens to solid particles when they are heated?

  They gain more energy and vibrate more
• What is the melting point?

  The temperature at which solid particles have enough energy to break free of their bonds
• What occurs when a solid melts?


  The solid turns into a liquid
• How are particles arranged in liquids?

  They are arranged randomly but are fairly compact
• Why do liquids have a definite volume but not a definite shape?


  Because the particles can flow to fit a container
• What happens to liquid particles when heated?

  They gain more energy and move around faster
• What is the boiling point?

  The temperature at which liquid particles have enough energy to break their bonds and turn into gas
• What occurs when a liquid boils?

  The liquid turns into a gas
• How do gas particles behave compared to solids and liquids?

  They are free to move around and do not have a definite shape or volume
• What does random motion of gas particles mean?

  Particles can travel in any direction and are deflected by walls and other particles
• What happens to gas particles when heated?

  They gain more energy and travel faster
• What happens to a gas in an expandable container when heated?

  The gas will expand
• What happens to a gas in a fixed container when heated?

  The pressure will increase
• What occurs when a gas is cooled down enough?

  Bonds will start to form between the particles, condensing the gas into a liquid
• What happens when a liquid is cooled down further?

  More bonds form, fixing the particles in place and freezing the liquid into a solid
• What happens to mass in a closed system during changes in state?

  The mass remains the same as the number of particles does not change
• How does the density of substances compare among solids, liquids, and gases?

  Solids have the highest density, liquids have lower density, and gases have the lowest density
• What are the changes of state for matter when heating and cooling?

  • Solid to liquid: Melting
  • Liquid to gas: Boiling or evaporation
  • Gas to liquid: Condensation
  • Liquid to solid: Freezing
• What are the characteristics of solids, liquids, and gases in terms of particle arrangement and movement?

  • Solids:
  • Fixed position
  • Strong forces of attraction
  • Definite shape and volume
  • Liquids:
  • Random arrangement
  • Weak forces of attraction
  • Definite volume, shape changes
  • Gases:
  • Free movement
  • Very weak forces of attraction
  • No definite shape or volume