ammonium

American  

[uh-moh-nee-uhm] / əˈmoʊ ni əm /

noun

Chemistry.

1. the univalent ion, NH 4 + , or group, NH 4 , which plays the part of a metal in the salt formed when ammonia reacts with an acid.

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ammonium British  

/ əˈməʊnɪəm, -njəm /

noun

1. (modifier) of, consisting of, or containing the monovalent group NH 4 – or the ion NH 4 ⁺

   ammonium compounds

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ammonium Scientific  

/ ə-mō′nē-əm /

1. A positively charged ion, NH ₄, derived from ammonia and found in a wide variety of organic and inorganic compounds. Compounds of ammonium chemically resemble the alkali metals.

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Etymology

Origin of ammonium

< New Latin; ammonia, -ium; coined by J. J. Berzelius in 1808

Compare meaning

How does ammonium compare to similar and commonly confused words? Explore the most common comparisons:

• ammonia vs. ammonium

Example Sentences

In 2024 China accounted for 70% of Russia’s imports of ammonium perchlorate, an essential ingredient in ballistic-missile fuel.

From The Wall Street Journal • Dec. 18, 2025

Davis said six packages of ammonium nitrate were shipped from Park in Seattle to Bartkus.

From Los Angeles Times • Jun. 24, 2025

Distillers threw rotten fruit and molasses waste in the gallon to brew with ammonium chloride to produce something called “snake juice,” which was collected by lepers and taken around the city.

From Salon • Feb. 2, 2025

Of the shipment waiting currently on the Zimrida, 7,600 tonnes of ammonium nitrate fertiliser is destined for use in Ivory Coast.

From BBC • Jan. 7, 2025

Ed McMillan had staged the Rad Lab’s most determined search for the isotope by propping a bottle of granular ammonium nitrate in the path of the thirty-seven-inch machine’s neutron beam for several months.

From "Big Science" by Michael Hiltzik