Hope this theoretical question isnt too stupid, just my physics teacher couldnt give me a satisfying answer and im only 14. (english is also not my mothertongue, pls excuse grammatical failures) So what if there was some sort of machine, that would just convert mass into energy after e=mc². If you were to feed this machine first with 1 kg of CO², you'd get 9 GJ. If you were then to feed this machine with the aquivalent of C and O needed to produce 1kg of CO², but seperatly, you'd still get out the 9 GJ. But what happend with the theoretical chemical Energy C and O has? Does it maybe get lost when C and O becomes plasma thus releasing the energy held by the angle of the electron pairs to eachother? So, doesnt that also mean, that no such machine could exist, without having to heat up the mass to a very high point?