How do I use the equation E=MC^2 in relation to atoms (not even sure it can be used for other things) to find the amount of energy of a reaction?

Question

anonymous · Answer

E=MC^2 works for everthing but it is most useful when the the energy of a reaction is comparable to the total energy of the component of the reaction.  for example in a nuclear reaction where then energy of the initial state and final may be several BeV and the reaction energy is of the order of MeV..  In the case of chemical reaction it  works too but the reaction energy is only of the order of eV which is 1000000 smaller than nuclear energies.  This means that to use this equation you must know the beginning and ending products to a precision comparable to the precision of the reaction energy.  This may be practically difficult.