particle model

• What model is used to explain the behavior of particles 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 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?

  Particles are fixed in position
• How do particles in solids behave?

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

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

  The temperature where solids melt
• What occurs at the melting point?

  Particles break free of their bonds
• What are the forces of attraction like in liquids?

  Weak forces of attraction
• How are particles arranged in liquids?

  Randomly, but fairly compact
• Why do liquids have a definite volume?

  Particles tend to stick together
• What happens when a liquid is heated?

  Particles gain energy and move faster
• What is the boiling point?

  The temperature where liquids boil
• What occurs at the boiling point?

  Particles break bonds and become gas
• How do gas particles behave?

  They move freely and randomly
• Why do gases not have a definite shape or volume?

  They fill the container they are in
• What does random motion of gas particles mean?

  They can travel in any direction
• What happens when a gas is heated?

  Particles travel faster and expand
• What happens to gas in an expandable container when heated?

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

  The pressure increases
• What happens when a gas is cooled down?

  Particles form bonds and condense
• What happens to a liquid when cooled further?

  Particles form more bonds and freeze
• What happens to mass in a closed system during state changes?

  Mass remains unchanged
• How does density vary among the states of matter?

  Solids are highest, gases lowest
• Which state of matter has the highest density?

  Solid
• Which state of matter has the lowest density?

  Gas
• What are the changes of state between solid, liquid, and gas?

  • Solid to liquid: Melting
  • Liquid to gas: Boiling or evaporation
  • Gas to liquid: Condensation
  • Liquid to solid: Freezing
• How does heating affect the states of matter?

  • Heating solids: Increases vibration, leads to melting
  • Heating liquids: Increases movement, leads to boiling
  • Heating gases: Increases speed, leads to expansion
• How does cooling affect the states of matter?

  • Cooling gases: Decreases energy, leads to condensation
  • Cooling liquids: Decreases energy, leads to freezing
  • Cooling solids: No significant change in state
• What is the relationship between temperature and state changes?

  • Temperature determines the state of matter
  • Each state has specific melting and boiling points
  • Energy changes lead to state transitions
• In a closed system, changes in state won't change the mass at all.

  Why is this the case?

  The number of particles remains the same
• Why do gases have the lowest density?

  the particles are spread out, with lots of empty space between them,