We report the formation of deuterium-terminated Si(111) and Si(100) surfaces in deuterated aqueous KF. The reaction of a deuterated Si(100) surface with H2O is investigated. We find that H2O etches the surface to give hydrogen termination and oxidized silicon hydrides. Hydrogenterminated surfaces react with various reagents under non-UHV conditions to form other covalent bonded species, including Cl-Si and Co(CO)4-Si. These species are characterized by polarized ATR and transmission FTIR. On Cl-Si(111) surfaces, Cl-Si is perpendicular to the surface. Chlorine-terminated Si(100) reacts with H2O to produce the hydrogen terminated surface. On Co(CO)4-Si(111) surfaces, one carbonyl is perpendicular to the surface, and the other three are approximately parallel to the surface.