The Distinction between Intrinsic and Spurious Contact E.M.F.S and the Question of the Absorption of Radiation by Metals in Quanta.

Abstract

Stopping potentials for photo-electrons from Na, K and Li surfaces, as determined with a Faraday cylinder in vacuo for monochromatic ultraviolet light, were found to be accurately the same for all. This result makes general the conclusion that the stopping potential for a given frequency is the same for all clean metals. It is not the same for an oxidized copper surface, however, or for any surface showing a spurious contact e.m.f.