Topic 14-particle model

• Density(kg/m^3)= mass(kg)/volume(m^3)
• What does density depend on

  how close its particles are to each other.
• Why does solid have highest density ?


  particles are very close together and the forces of attraction between them are strong.
• The kinetic theory model shows how particles are arranged in each state of matter.
• density: 1g/cm^2 = 1000kg/m^3 (waters density)
• What is specific heat capacity?

  Amount of energy it takes to raise tempature of 1kg of that substance by 1°c
• What is water specific heat capacity

  4200J/kg°C
• What is specific heat capacity measured in?

  J/kg°C
• Change in thermal energy = mass × specific heat capacity × change in tempature
• What is latent heat?

  Energy needed for substance to change state
• When substance changes state

  The energy supplied increase internal energy stored but not change temperature of substance
• What is specific latent heat?

  Energy required to change state of 1kg of substance with no change in temperature
• Thermal energy for change of state(J) = mass(Kg) × specific latent heat (J/kg)
• What is thermal insulation for?

  Reduced unwanted energy transfers
• Reduced unwanted energy transfer

  • Air gaps
  • Loft insulation
  • Double glazing of windows
• What is used to miniseries energy transfers

  Materials that are poor conductors
• Why do some systems need more energy than others to warm up?

  Made of different substances
• Why are changes of state physical changes?

  Changes are reversible
• What is tempature of gas proportional to?

  Kinetic energy of particles
• Average kinetic energy of particles is directly proportional to tempature of gas in kelvin
• Tempature in kelvin = tempature in celsius + 273
• What is absolute 0?

  Lowest tempature particles have motion
• Absolute 0 = -273