Exothermic and endothermic reactions GapFill

Energy is always  createddestroyeddiscoveredconservedprovidedreleased during chemical reactions. There may be a change in the  magnetismpolaritycolourhumiditytemperaturepressure of the surroundings due to energy being taken in or given out by the molecules. Reactions in which the surroundings get warmer are called  oxidativeexothermicyieldinggenerativeproductiveheating, e.g. combustion,  burningprecipitationminingactivationneutralisationpolymerisation and the reactions of  food colouringsdehumidifiersmake-up removersair conditionershand warmerssports injury packs, and reactions in which they get colder are called  unproductiveendothermicresistingcoolingsterilisingreductive, e.g. thermal  distillationoxidationchromatographydecompositionhydrogenationfractionation reactions. Reactions will only occur if particles collide with sufficient  anglesorientationsdirectionsmassestangentsenergy.

One way of representing reactions is using a reaction  profilemodelboardgradienttableslider, which shows the energy of the reactants and products. The height of the curve from the reactants is the  total energyenergy peakactivation energymaximum reactivityenergy debtinitiation energy, and the difference between the reactants and products is the  energy costtotal energyactivation energyenergy productenergy pay-offenergy change of the reaction.