Answer:
Chemical energy is stored in the bonds between atoms within a molecule. Specifically, the potential energy of the electrons in the chemical bonds represents the chemical energy of the molecule.
When a chemical reaction occurs, the bonds between atoms in the reactant molecules are broken, and new bonds are formed to create products. This rearrangement of atoms results in the release or absorption of energy, depending on whether the reaction is exothermic or endothermic.
In an exothermic reaction, energy is released from the molecule as the bonds are broken and reformed. This energy can take many forms, including heat, light, or sound. For example, the combustion of gasoline in a car engine is an exothermic reaction that releases energy in the form of heat and kinetic energy, which powers the car.
In contrast, in an endothermic reaction, energy is absorbed by the molecule as the bonds are broken and reformed. This energy typically comes from the surroundings, such as heat or light. An example of an endothermic reaction is photosynthesis, in which energy from sunlight is absorbed by chlorophyll molecules to convert carbon dioxide and water into glucose and oxygen.