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  • Heat and temperature are not the same thing
  • Temperature is a measure of how hot things are
  • The Celsius scale of temperature is used in science
  • The values of the boiling point (100oC) and freezing point of water (0oC) on the Celsius scale must be recalled and so should some typical day to day temperatures: body temperature is 37oC, room temperature is about 20oC
  • There are different kinds of thermometer
  • Heat is a form of energy measured in joules (J)
  • Heat flows as a result of temperature differences - from hot to cold - the bigger the temperature difference the faster the heat flows
  • Heat moves in three ways: conduction, convection and radiation
  • Heat energy will flow more easily (more quickly) through good thermal conductors and less well (more slowly) through poor conductors
  • Metals are good thermal conductors because they can use electrons to carry heat energy as well as simply passing on heat to neighbours by vibrations.
  • Poor thermal conductors are called insulators
  • Liquids and gases are poor thermal conductors.
  • Evidence of conduction in solids, liquids and gases can be explained using the particle model
  • Vibration of particles in solids, liquids and gases increases with increasing temperature and the particles move further apart because of increased vibration making the object expand on heating.
  • Expansion of a material will reduce its density because the volume will increase but the mass remain the same.
  • Convection - that hot fluids rise due to expansion and cooler ones sink to take their place
  • that expansion of fluids causes a change (decrease) in density
  • Use the particle model to explain convection in fluids
  • Radiation energy (infrared) is like light energy - travels in straight lines, gets reflected and can travel through a vacuum
  • Insulation can reduce unwanted energy transfer
  • Use the particle model to explain changes of state
  • Solids, liquids and gases can change state when energy is added or removed and these changes are reversible
  • Changes of state occur at fixed temperatures (called the boiling point and melting point)
  • Draw an appropriate best-fit curve/line to fit quantitative data on a graph