Photons are referred to as the field quanta for the electromagnetic field. I would like to understand how the exchange of field quanta such as photons can create an attractive force. For example, I can see that an electron could repel another electron by hitting it with photons. (radiation pressure ?) How can the exchange of photons create an attractive force, though ? For example, how does the exchange of photons cause the attraction of an electron to a proton ? If a proton emits photons that hit an electron, then Newton's third law would suggest that the electron and the proton should repel each other. Please forgive my naivete if this type of simplistic "billiard ball" physics does no apply to elementary particles.