Particle model

• 3 states of matter

  . Solid

  . Liquid

  . Gas
• 5 changes of state

  . Melting

  . Evaporation

  . Condensation

  . Freezing

  . Sublimation
• Arrangemeny of particles in a solid:

  . Close together

  . Regular arrangement

  . Strong forces
• Movement of particles in a solid:

  Vibrate around a fixed position
• Arrangement of particles in liquid:

  Close together

  Random arrangement

  Strong forces
• Movement of particles in a liquid:

  Move freely
• Arrangement of particles in gas:

  Far apart

  Random arrangement

  Weak forces
• Arrangement of particles in gas:

  Far apart

  Random arrangement

  Weak forces
• Movement of particles in a gas:

  Move freely and rapidly
• During a change of state as particles are heated, they gain enough energy to overcome forces and move faster
• During a change of state as particles are cooled, they lose energy and forces become stronger so they move slower
• Internal energy- The total kinetic energy and potential energy of all the particles that make up a system.
• Gas has most internal energy
• As particles are heated kinetic energy increases
• Specific heat capacity- Energy required to heat 1kg of a substance by 1°C.
• Units for specific heat capacity are J/kg°C
• How do you measure specific heat capacity?

  Mass: electronic balance

  temperature change: thermometer

  energy: power of heater x time heated.

  SHC = energy + (mass x temp. change)
• you insulate the material when measuring its specific heat capacity to prevent heat loss and measure an accurate temperature change
• Specific latent heat - Energy required to change state of 1kg of a substance without changing its temperature
• Specific latent heat - Energy required to change state of 1kg of a substance without changing its temperature
• Temperature doesn't change during change of state because energy is used to overcome forces instead of Increasing kinetic energy.