The chemical compound with the formula NH₃ commonly known as ammonia is ammonia.
Ammonia is a colorless gas made from one nitrogen atom and three hydrogen atoms. It has a sharp, distinctive odor and dissolves readily in water, producing an alkaline solution. In water, some ammonia reacts with water molecules to form ammonium and hydroxide ions, which explains its basic behavior.
Industrial ammonia is produced mainly by the Haber process, in which nitrogen from the air reacts with hydrogen under high pressure and temperature in the presence of a catalyst. The resulting ammonia is used extensively to manufacture nitrogen fertilizers, including urea and ammonium nitrate. Fertilizer production makes ammonia one of the most important industrial chemicals worldwide.
Ammonia is not the same as ammonium, which is the positively charged ion NH₄⁺. Household ammonia solutions also differ from pure ammonia gas because they contain ammonia dissolved in water. Strong exposure can irritate the eyes, skin, and respiratory system, so concentrated ammonia must be handled carefully.