Where Does The Loss of Mass Occur When an Exothermic Reaction Occurs?

[andrewcellini]

I saw AJB say that the mass of a free electron + free proton is larger than that of a hydrogen atom....why is that?

the mass of hydrogen is lighter because of the binding energy which is negative.

 

m = mp + me - E/c^2

 

m is mass of hydrogen (in ground state), mp mass of proton, me mass of electron and E/c^2 is the mass contribution due to the binding energy. the energy required to separate the electron is equal to the absolute value of the binding energy.

 

https://en.wikipedia.org/wiki/Binding_energy

Edited December 5, 2015 by andrewcellini