the energy differently. Exoergic, or exothermic, reactions release energy during the reaction. Combustion is one of the major reactions that do this. The burning of wood, or any other fuel, gives off heat, and the burning of glucose in our bodies gives off both energy and heat. Endoergic, or endothermic, reactions absorb energy during the reaction. The melting of an ice cube is an example of an endothermic reaction. Aergic, or athermic, reactions neither give off nor absorb energy. There are very few cases in which this happens. There are some things that must be considered in a chemical reaction. Kinetics is one of these things. Kinetics decides The speed of the reaction and what is happening on a molecular level. There are a few things that decide the course and speed of the reaction. The first thing is the reactants. Different reactants react at different speeds. Even the position of the reactants will affect the reaction rate. Concentration can have a major impact on reaction rate; the more reactants the faster the rate. Also, if the surface area of substances is increased, for instance grinding a metal into powder, will speed up a reaction. Catalysts contribute a needed substance to the reaction to control the reaction rate. They are responsible for lowering the activation energy. The catalyst is an outside substance that is included in the reaction, but is not consumed during the reaction like the reactants are. They cannot make impossible reactions occur, they only contribute to the reaction to increase the reaction rate. There are also such things as negative catalysts, or inhibitors. Inhibitors retard the reaction rate. This is also a way to control reactions. A good example in nature of a catalyst is in a firefly. The reaction that releases the light is complex. Lucifern, which the firefly makes naturally, is oxidized in the presence of luciferase, another natural enzym...
