Ammonium is a compound radical or ion NH4+ and is not on the periodic table.
Ammonia is a weak base; in solution, it forms the ammonium ion, NH4+, which is the form that nitrogen is found in most fertilizers, in the salts ammonium nitrate, NH4NO3, and ammonium sulfate, (NH4)2SO4.
Ammonia is one of the most commonly produced industrial chemicals in the United States. It is used in industry and commerce, and also exists naturally in humans and in the environment. Ammonia is essential for many biological processes and serves as a precursor for amino acid and nucleotide synthesis. In the environment, ammonia is part of the nitrogen cycle and is produced in soil from bacterial processes. Ammonia is also produced naturally from decomposition of organic matter, including plants, animals and animal wastes.
Some chemical/physical properties of ammonia are:
At room temperature, ammonia is a colorless, highly irritating gas with a pungent, suffocating odor.
In pure form, it is known as anhydrous ammonia and is hygroscopic (readily absorbs moisture).
Ammonia has alkaline properties and is corrosive.
Ammonia gas dissolves easily in water to form ammonium hydroxide, a caustic solution and weak base.
Ammonia gas is easily compressed and forms a clear liquid under pressure.
Ammonia is usually shipped as a compressed liquid in steel containers.
Ammonia is not highly flammable, but containers of ammonia may explode when exposed to high heat.
Learn more facts about Ammonia at New York State Department of Health.
Tip! Find out how to learn the periodic table in 3 minutes shared by CNET.