>be me, hydrocarbon floating about chillin
>bump into asshole in my way
>hit him pretty fuckin hard
>lol bye hydrogens, I’m riding with oxygen now
>stupid slutty hydrogens shacked up with oxygen too
>mfw when all electrons, protons and neutrons in the system are still accounted for, but now all the other floating chemicals around me move faster.

I know I’m thinking about endothermic reactions wrong, but I don’t understand why this process, even though it doesn’t seem to eject any mass, releases heat energy. My professor last semester made us memorize that when bonds form they release energy, but what does that really mean? What is actually being released? I suppose photons would be the answer, but where then would photons be stored in the molecule? They are released from electrons moving to different orbitals, but why?