The term "energy" in the context of chemical bonds and dissociation refers to the potential energy stored in the chemical bonds between atoms within a molecule. When chemical bonds are formed between atoms to create a molecule, energy is typically released, and this process is exothermic. Conversely, when chemical bonds are broken during dissociation, energy is usually absorbed, and this process is endothermic.
To clarify, let's discuss this in terms of energy changes during chemical reactions:
Bond Formation (Exothermic Reaction): When atoms come together to form a molecule, chemical bonds are created, and this process releases energy. This is because the newly formed molecule has lower potential energy compared to the individual atoms before bonding. The energy difference is released in the form of heat or other forms of energy. This is an exothermic reaction.
Bond Dissociation (Endothermic Reaction): When a molecule undergoes dissociation, the chemical bonds between its atoms are broken, requiring an input of energy. The energy is absorbed to break these bonds, and the resulting products (individual atoms or smaller molecules) have higher potential energy than the original molecule. This is an endothermic reaction.
So, in summary, energy is released during bond formation (exothermic) and absorbed during bond dissociation (endothermic). The overall energy change in a chemical reaction is determined by the difference between the energy released in bond formation and the energy absorbed in bond dissociation. This principle is fundamental to understanding energy changes in chemical reactions and is an essential concept in chemistry.