Chemical Reactions - Part III 3. The chemical reaction on a microscopic level is nothing but breaking and making bonds between the reactant compounds involved in the reaction. The missing mass goes to forming the bonds between the atoms.
All chemical reactions proceed in the direction of attaining greater binding energy.
Greater the binding energy, more difficult it is to break the compound and hence it is more stable. Lower down the compound is, tighter is the binding. The adjacent figure is not drawn to scale but depicts what happens when a free Oxygen atom combines with free Hydrogen atoms. Mole is a measure of the mass involved in chemical reactions, since it is not possible to calculate energy changes on atomic levels. We will study more about moles later in the chapter.