The course of time-resolved experimental studies of light emission from excited states produced by pulse radiolysis of rare gases, and rare gases containing trace additives, is summarized. The mechanisms leading to the observed excited states are described and related to the interaction of subexcitation electrons with the trace component of the gaseous solution. Kinetic parameters for the subexcitation electron interactions are summarized for a number of chemical systems, and the experimental results are compared with theoretical models which use known energy loss cross-sections for electrons. Recent results are presented for the production of excited states in low pressure of pure rare gases. These studies show the effects of secondary electrons prior to the formation of the subexcitation electron spectrum.