Hydrogen telluride is a toxic reactive gas. It easily decomposes to hydrogen and tellurium. It also burns in air to make tellurium dioxide and water. It has a very bad smell of decayed garlic. It is almost as acidic as phosphoric acid. It reacts with some metals and metal oxides to make tellurides.
It is made by adding a strong acid to a telluride, such as sodium telluride.
Hydrogen telluride does not have many uses because it is very toxic and unstable.