What is the physical vehicle for transfer of energy in a chemical reaction?

Question

In an exothermic chemical reaction, how is energy released? Usually it is simply expressed as reactants -> product + energy. But how is that energy emitted?

I understand the release of electromagnetic energy through photons, but what other vehicles are there? Do the molecules gain random kinetic energy? Is it vibrational energy (phonons)?

Answer 1

transfer of kinetic energy is one of the ways, which of course is manifested as heat. there is also change in mass (by very small amounts) but to describe this, you need a pretty thorough understanding of quantum physics

Answer 2

Endothermic and exothermic chemical reactions could do the rearrangements of molecules and atoms. The Einstein equation has to do with the rearrangement of protons and neutrons.