Which type of energy is primarily stored in the bonds of chemical substances?

Chemical energy is primarily stored in the bonds of chemical substances. This form of energy arises from the arrangement of atoms within molecules. When chemical bonds between atoms are formed or broken during chemical reactions, energy is absorbed or released. For example, during combustion, the breaking of bonds in reactants releases energy in the form of heat and light, highlighting how chemical energy is directly involved in energy transformations within a system.

In contrast, nuclear energy is associated with the forces and reactions within an atomic nucleus, while electrical energy relates to the movement of electrons through a conductor. Thermal energy denotes the total kinetic energy of particles in a substance, which is related to temperature but does not specifically involve chemical bonds. Therefore, the focus on chemical bonds clarifies why chemical energy is the correct choice for this question.