We have investigated the thermally-induced and electron-impact-induced chemistry of CF₃I on Ni(100) following adsorption at 100 K. The data support a model for the thermally-induced chemistry, in which CF₃I dissociates to CF₃ and I, either upon adsorption or at slightly-elevated temperatures. Most CF₃ decomposes to adsorbed C and F. Above 75% saturation of the first layer, the availability of surface sites for decomposition decreases to a level where some adsorbed CF₃ remains intact and desorbs as such. Bombardment of multilayer CF₃I by lowenergy electrons introduces new chemistry. Electron-induced decomposition (EID) of the parent molecule occurs through both C-I and C-F bond scission, with a measured cross section of 1.5 X 10^-16 cm² (upper limit). Thermally-induced desorption from the electron-bombarded surface indicates a number of EID fragment reactions, most notably carbon - carbon bond formation, as evidenced by C₂F₃I+, C₂F₄ +, C₂F₅ +, C₃F₅ +, and C₄F₇ +. To our knowledge, this is the first report of C-C bond formation in small fluorocarbons adsorbed on metal surfaces.