Which compound, NH₃, is commonly called ammonia?

Ammonia is the compound with the chemical formula NH₃.

An ammonia molecule contains one nitrogen atom bonded to three hydrogen atoms. It is a colorless gas with a sharp, characteristic odor and is highly soluble in water. When ammonia dissolves in water, it participates in an equilibrium that produces ammonium and hydroxide ions, making the solution alkaline.

Ammonia is central to modern fertilizer production. The Haber process combines nitrogen and hydrogen to make ammonia on an industrial scale, providing a starting material for fertilizers such as ammonium nitrate and urea. This chemistry greatly increased agricultural productivity but also contributes to environmental problems when excess nitrogen enters waterways.

Ammonia is not the same as ammonium, NH₄⁺, which is a positively charged ion formed when ammonia accepts a proton. Household cleaning products may contain dilute ammonia solutions, but concentrated ammonia can irritate or burn tissues and must be handled carefully.