Hydrogen Selenide is a chemical compound with the formula H2Se. It consists of two hydrogen atoms bonded to one selenium atom. This colorless gas has a distinct, unpleasant odor similar to that of rotten eggs. It is highly toxic and can be harmful if inhaled or ingested. In nature, Hydrogen Selenide can be found in volcanic gases and as a byproduct of certain industrial processes. It is used in the production of selenium and in various chemical reactions. Due to its toxicity, proper safety measures are essential when handling this compound.