The three states of matter

• What does the kinetic particle theory of matter describe?

  The arrangement, movement, and energy of particles in a substance
• How does the kinetic particle theory explain the physical properties of solids, liquids, and gases?

  It describes how particle arrangement and movement affect their properties
• What types of particles can be represented in the diagrams of states of matter?

  • Atoms
  • Molecules
  • Ions
• Why does a single particle not have the properties of the material it is part of?

  Because the properties arise from a large number of particles together
• What are the properties of solids?

  • Fixed shape
  • Cannot flow
  • Cannot be compressed
• What are the properties of liquids?

  • Flow and take the shape of their container
  • Cannot be compressed
• What are the properties of gases?

  • Flow and completely fill their container
  • Can be compressed
• What is sublimation?

  • Direct change from solid to gas
  • Example: Solid carbon dioxide ('dry ice')
• What must happen for changes of state like melting, evaporating, and boiling to occur?

  Energy must be transferred to the substance by heating
• What happens to particles during melting?

  They gain energy to break some of the bonds between them
• How do particles behave during evaporation compared to boiling?

  In evaporation, particles leave from the surface; in boiling, bubbles form throughout the liquid
• What determines the amount of energy needed to change state?

  The strength of the forces between the particles of a substance
• What is the melting point of sodium chloride?

  801°C
• What is the boiling point of water?

  100°C
• Why does evaporation occur below the boiling point?

  Because particles at the surface can gain enough energy to escape
• What happens to energy during condensing and freezing?

  Energy is transferred from the substance to the surroundings
• How can the state of a substance at a given temperature be predicted?

  • If temperature < melting point: Solid
  • If temperature is between melting and boiling points: Liquid
  • If temperature > boiling point: Gas
• What are the limitations of the particle model?

  It assumes particles are solid spheres with no forces between them
• Why are particles not considered solid in the particle model?

  Because atoms are mostly empty space
• Why might many particles not be spherical?

  Because different types of particles have different shapes