chemical reactions,\xa0bondsbetween\xa0atoms\xa0in the reactants must be broken, and the atoms or pieces of\xa0molecules\xa0are reassembled into products by forming new bonds. Energy is absorbed to break bonds, and energy is evolved as bonds are made. In some reactions the energy required to break bonds is larger than the energy evolved on making new bonds, and the net result is the\xa0absorption\xa0of energy. Such a reaction is said to be endothermic if the energy is in the form of\xa0heatThe opposite of\xa0endothermic\xa0is exothermic; in an\xa0exothermic reaction, energy as heat is evolved
If more energy is released than the energy consumed, then heat is evolved and the reaction is known as an exothermic reaction