High School Mass defect and electron transition

[sandeepts]

TL;DR

Mass defect and electron transmission

According to STR: E=MC^2.

When an electron and proton are independent( without influence of any kind of fields, especially electrostatic fields )their rest masses are Me and Mp. When they combine to form Hydrogen atoms they emit photons. So, some energy loss in the form of photons. So, now mass of proton and electron in the hydrogen are Me H and MpH. Which is Me and Mp less than Me H and MpH. ( Me > Me H , Mp>MpH ). So, the energy of photons is contributed by electrons as well as protons. Am I right or wrong?

 

[Nugatory]

So, now mass of proton and electron in the hydrogen are Me H and MpH

No, the mass of the electron is unchanged, as is the mass of the proton.. The mass of a multi-particle system is generally not equal to the sum of the masses of the particles, so there’s no reason to expect that the mass of a hydrogen atom must be equal to the sum of the electron and proton masses.

This may make more sense if you imagine that we start with a hydrogen atom, pull the electron out, and move it far far away. Doing this was work, so we had to add some energy to the electron/proton system to get to where we could think of them as “independent”. And that’s the energy that is released when we allow them to recombine.

 

[Orodruin]

TL;DR Summary: Mass defect and electron transmission

Am I right or wrong?

Wrong. It is contributed by the proton-electron system. This system includes the electromagnetic field configuration as well as the particles themselves. You cannot assign a particular number coming from the proton and a particular number coming from the electron. It simply does not make sense.

 

[Herman Trivilino]

So, the energy of photons is contributed by electrons as well as protons.

No. The energy of the photons is contrbuted by the electron-proton system. The lesson of the Einstein mass-energy equivalence is that energy makes a contribution to the mass of a system.

Attempts to account for this contribution by altering the masses of the constituents ignore the lesson and instead attempt to resurrect the erroneous newtonian notion that the mass of a system equals the sum of the masses of its constituents. I find it ironic.