A Direct Experimental Determination of the Electron Affinity of Oxygen

Abstract

The electron affinity of oxygen atoms for one electron, the negative of the energy change at absolute zero of the reaction $$e^{-}+{\mathrm{O}}_{\mathrm{gas}}\to {\mathrm{O}}_{\mathrm{gas}}^{-},$$ has been determined to be 70.8±2.0 kcal./mole. The method used was to determine the ratio of negative ions to electrons leaving a hot filament surface exposed to oxygen gas at a low pressure.