Ammonia is an azane that consists of a single nitrogen atom covelently bonded to three hydrogen atoms. It has a role as a nucleophilic reagent, a neurotoxin, a metabolite, an EC 3.5.1.4 (amidase) inhibitor, a refrigerant, a mouse metabolite and a NMR chemical shift reference compound. It is an azane, a mononuclear parent hydride and a gas molecular entity. It is a conjugate base of an ammonium. It is a conjugate acid of an azanide.