Chemical+Energy

Chemical energy is in bonds between atoms (remember UV light broke O-O bonds) Energy is either released (exothermic) or consumed (endothermic) depending upon the strengths of the bonds in reactants and products.

If the total strength of the bonds in the products is greater than the total strengths of the reactants, then the reaction will be exothermic Exothermic reactions require bond breaking to cost less energy than bond making
 * Exothermic reaction:** energy is released


 * Endothermic reaction:** energy is consumed