Heat energy changes in chemical reactions GapFill

Energy is always  conservedcreateddestroyedprovided during chemical reactions. There may be a change in the  humiditytemperaturecolourpressure of the surroundings due to energy being taken in or given out by the molecules. Reactions in which the surroundings get warmer are called  generativeproductiveheatingexothermic, e.g. combustion,  neutralisationpolymerisationburningprecipitation and the reactions of hand warmers, and reactions in which they get colder are called  unproductiveendothermicsterilisingcooling, e.g. thermal  chromatographyoxidationdecompositiondistillation reactions. Reactions will only occur if particles collide with sufficient  anglesdirectionsorientationsenergy.

One way of representing reactions is using a reaction  profileboardmodeltable, which shows the energy of the reactants and products. The height of the curve from the reactants is the  activation energyenergy peakmaximum reactivitytotal energy, and the difference between the reactants and products is the  energy changeenergy pay-offenergy costtotal energy of the reaction.

When bonds are  reshapedheatedcreatedbroken in the reactants, energy is taken in. When bonds are  reactedunravelleddestroyedformed in the products, energy is released. A reaction is exothermic if the energy released is  not equal togreater thanequal toless than the amount taken in.