Answer: Chemical energy is energy stored in the structure of molecules within the bonds between atoms. Energy can be added or released from a molecule by changing the arrangement of electrons (rearranging chemical bonds).
Energy is absorbed to break bonds. Bond-breaking is an endothermic process.
Energy is released when new bonds form. Bond-making is an exothermic process.
Whether a reaction is endothermic or exothermic depends on the difference between the energy needed to break bonds and the energy released when new bonds form.
