|MadSci Network: Chemistry|
I am not an expert in this area, but like you have an enduring interest in this kind of question. If you want to send another question to clear things up after I have taken a stab at it, I will not be at all offended. I want to congratulate you on a very deep question, and one that took a lot of work to understand on a fundamental level. Quantum electrodynamics (QED) and quantum field theory require that any interaction be mediated through interactions between quantized entities. Each type of interaction has its own force carrier. In the case of the electromagnetic force, which is the one you asked about, the force carriers between electrically charged particles are photons. The fact that photons are massless, means that the range of potential interactions is essentially infinite. In quantum field theory, the field established by each charge and its intensity determines the probability that a virtual photon (or other force carrier for the other types of forces) will be created from the field and travel to one or the other of the charged paticles and thus "nudge" it in the direction determined by the other charge. This happens so many times that the particles appear to have smooth acceleration when the model says they are having multiple mutual bumps from the photons they are "throwing" at each other. The Feynmann diagrams explicitly illustrate charged particles exchanging photons. See: http://www2.slac.stanford.edu/VVC/theory/feynman.html.
Try the links in the MadSci Library for more information on Chemistry.