Energy is stored between the bonds of an atom in a molecule therefore it is potential energy so it has not been release yet.
Molecules and atoms contain kinetic energy so they are always in motion. By the collision of molecules
While a chemical reaction is happening the activation energy is absorbed so it can break the chemical bonds that exist. As the new bonds form energy is always released from a chemical reaction.
If the bonds of the reactants contain less energy than the bonds of the products, the overall reaction absorbs energy (endothermic).
The sign of endothermic is positive because the temperature is cold. An example is Ammonium Nitrate is +25,400J and this chemical is cold.
Ig the bonds of the reactants contain more energy than the bonds of the products, the overall reaction releases energy (exothermic).
The sign of exothermic is negative because the temperture is hot. AN example is Calcium Chloride is -80,000J
The potential energy of the bonds of the products depends on the reaction. The product releases the energy and loses it if it is an exothermic reaction. And the product absorbs the energy and gains it if it is endothermic.
No matter the type of chemical reaction, the total amount of energy will always remain the same in the system and surroundings.