tellurium(vi) fluoride is a colorless gas. it condenses to a white solid when made cold. it has a very bad smell. it is very toxic. it is similar to selenium hexafluoride, even though it is less volatile (not as easily evaporated). it reacts with water to make telluric acid and hydrofluoric acid. it reacts with tellurium under to make tellurium tetrafluoride.