Reactions of free electrons in the gas phase, of quasi-free electrons and solvated electrons in dielectric liquids, of hydrated electrons in water, and of electrons originating from an electrode in contact with a solution are among the great variety of electronic processes in chemistry. It is the purpose of this paper to describe a few phase effects. Reactions of electrons in dielectric liquids will be discussed with respect to the corresponding processes in the gas phase. Furthermore, certain aspects in the transfer of an electron from a hydrocarbon phase into the aqueous phase will be dealt with. The processes will be described in terms of electronic redox level distributions of the acceptor redox systems.