A large proportion of healthy African Americans have been observed to have a white blood cell count (WBC) that is persistently lower than the normal range defined for individuals of European ancestry [1]â[5].
Energy is only released when chemical bonds are formed. In general, a chemical reaction involves two steps: 1) the original chemical bonds between the atoms are broken, and 2) new bonds are formed. These two steps are sometimes lumped into one event for simplicity, but they are really two separate events.
Chemical Energy Examples. Chemical energy is one of the many forms of energy that exist in the universe around us. Chemical energy can be released of absorbed during a chemical reaction. In order for a chemical reaction to occur, a substance or substances must change into new substances with different properties. When this occurs, chemical energy can released, an exothermic reaction or chemical energy can be absorbed, an endothermic reaction. When a reaction is exothermic, heat is released or you feel warmth, if it is endothermic, the heat is absorbed and we feel the substances cool down.