The concepts of cavity potential (electrostatic potential in a cavity in a conductor) and Fermi potential (energy per unit charge for an electron at the Fermi level) are defined and used to discuss the work function, contact potentials, Ohm's law, electrode-solution equilibria, and chemical emf's. With the introduction of the entropy transport per unit charge for electrons in a metal (S*), the Seebeck, Peltier, and Thomson effects are elucidated, and the fact that no emf exists at a thermal junction is made clear. Certain other common confusions are cleared up. It is suggested that use of this conceptual scheme will allow the basic physics of these important processes to be taught effectively in general physics courses.