physics kinetic theory

• What is the arrangement of particles in gases?


  The particles are widely spaced and scattered at random throughout the container.
• How do gas particles move?


  Gas particles move rapidly in all directions.
• Why do gases have a very low density?


  Because the particles are very far apart in the container.
• What is the order of density among solids, liquids, and gases?


  Density order: solid > liquid > gases.
• What is the force of attraction between particles in liquids compared to gases?


  There are much greater forces of attraction between the particles in liquids compared to gases.
• How do particles in liquids move?


  Particles in liquids move rapidly in all directions.
• Why do liquids have a much greater density than gases?


  Because the particles are much closer together due to attractive forces.
• What is the arrangement of particles in solids?


  Particles in solids pack together as tightly as possible in a neat and ordered arrangement.
• How do particles in solids move?


  Particles in solids vibrate about their position in the structure.
• Why do solids have the greatest density?

  Because the particles are closest together.
• What are the differences between physical changes and chemical changes?


  • Physical changes are reversible.
  • Chemical changes are non-reversible.
• What is the process of changing from liquid to gas called?

  Boiling or evaporation.
• What happens to particles when they are heated?

  Particles gain kinetic energy and move faster, overcoming intermolecular forces.
• What is required for particles to become a gas from a liquid?


  Energy is needed to overcome the attractive forces between particles.
• What is the process of gas turning into liquid called?

  Condensation.
• What happens to gas particles when they cool down?


  Gas particles lose kinetic energy and become attracted together to form a liquid.
• What is the relationship between temperature and the order of particles in a liquid when it cools?


  There is an increase in order as the particles become much closer together.
• What is the process of solid turning into liquid called?

  Melting.
• What happens to particles when a solid is heated?


  Particles vibrate more strongly as they gain kinetic energy, weakening attractive forces.
• What occurs at the melting point of a solid?


  The attractive forces are too weak to hold the particles in an ordered way, and the solid melts.
• What happens to the arrangement of particles when a solid melts?


  The particles become free to move around and lose their ordered arrangement.
• What is required for a solid to melt?

  Energy is needed to overcome the attractive forces and increase kinetic energy.
• What happens to liquid particles when they cool down?


  Liquid particles lose kinetic energy and become more strongly attracted to each other.
• What is the density of ice compared to water?


  Ice has a density of 0.9 g/cm³ and water has a density of 1.0 g/cm³.
• What does the difference in density between ice and water indicate about the spacing of molecules?


  The spacing of molecules is greater in ice than in water.
• How do solids change to liquids according to the kinetic theory?


  Energy is supplied through heating, causing particles to vibrate more strongly and weaken attractive forces.
• How do liquids change to gases according to the kinetic theory?


  Energy is supplied through heating, allowing particles to gain kinetic energy and overcome attractive forces.
• What happens to molecules in a solid when it changes into a liquid?


  Heating increases kinetic energy, causing molecules to vibrate more strongly and weaken forces of attraction.
• What is the density of water compared to ice?


  Water has a density of 1.0 g/cm³, which is greater than ice's density of 0.9 g/cm³.
• What does the difference in density between ice and water imply about their molecular structure?


  It implies that the spacing of molecules is greater in ice than in water.