Photon exchange in molecular bonds

[Ocata]

So a photon is absorbed into and emitted from electrons, causing the electrons to jump energy levels around an atomic nucleus. And enough energy absorbed into the electron will cause the electron to break from the atom altogether.

My question is, where does this energy that enters the electron come from? From what I gather, the energy can only come from photons since the photon is the only "force carrier" for electrons.

So when an atom with a strong positive charge travels near an atom with available electrons, the two atoms interact in various ways.

1) If the electron jumps from one atom to another atom, can it be due to a photon exchange between the electron of atom "a" and the proton of atom "b?"

2) If the two atoms form a bond, is it due to photons being exchanged between the electron(s) of atom "a" and protons of atom "b?"

Thanks

 

[Sophrosyne]

So a photon is absorbed into and emitted from electrons, causing the electrons to jump energy levels around an atomic nucleus. And enough energy absorbed into the electron will cause the electron to break from the atom altogether.

My question is, where does this energy that enters the electron come from? From what I gather, the energy can only come from photons since the photon is the only "force carrier" for electrons.

So when an atom with a strong positive charge travels near an atom with available electrons, the two atoms interact in various ways.

1) If the electron jumps from one atom to another atom, can it be due to a photon exchange between the electron of atom "a" and the proton of atom "b?"

2) If the two atoms form a bond, is it due to photons being exchanged between the electron(s) of atom "a" and protons of atom "b?"

Thanks

In quantum field theory and quantum electrodynamics, the photons in such electromagnetic exchanges are "virtual photons". They arise spontaneously out of the mathematics of the interaction. But they tend to get treated and interpreted a little differently than "real" photons. There are even folks who interpret it so that such photons don't necessarily have to even exist. You can't really detect such virtual photons.

I would recommend getting familiar with quantum electrodynamics and field theory in general. It might make a little more sense then.

As far as your 2 questions at the end, you can't really think of electrons around atoms or molecules as distinct objects that "jump" around from one atom to another (although I know that is how it is presented in introductory chemistry classes). Before measurement, they just form probability clouds around the nuclei called orbitals. Their shapes can be calculated using the Schrödinger wave equation in single atoms, and, in the case of molecules, using Hartree-Focke approximations. But without measuring, you can really not know anything about the position of anyone particular electron. It could theoretically be on Mars as far as we would know before checking.

 

[A. Neumaier]

Except in photochemistry, molecules are primarily described by electrostatic interactions, between systems of electronis in the ground state - not involving photons at all. Chemical bonds are essentially paired electrons. To understand the basics, read about the Hartree-Fock method.