INTERNAL ENERGY The sum of the kinetic energies and potential energies of all the atoms and molecules in a substance.HEAT The form of energy that transferred between two substances because they have different temperature.TEMPERATURE The average energy in a system.MYTH: FOOD CALORIE IS NOT A CALORIEThe food calorie that dieters count is not the same as standard calorie. In fact1food calorie = 1kilocalorie = 1000 calorieThe food calorie is used as a measure of the energy content in food. In Britain, though, this energy is listed on packing in joules.