ENGLISH
REFERENCE

ammonium

n. uncountable
C1 Advanced US //əˈmoʊniəm// UK //æmˈəʊniəm// am·mo·ni·um

n. a chemical part made of nitrogen and hydrogen that is found in many fertilizers and cleaning products. It is often part of a larger chemical compound rather than existing on its own.

n. a positively charged polyatomic ion with the chemical formula NH4+. It is formed by the protonation of ammonia and typically exists as a component in various salts and chemical compounds.


SIMPLE

The soil test showed high levels of ammonium.

CONTEXTUAL

Farmers often apply ammonium nitrate to their fields to provide essential nitrogen for crop growth.

COMPLEX

In aquatic environments, the balance between ammonia and ammonium is highly dependent on the pH level, with more acidic water shifting the equilibrium toward the less toxic ion.

Origin

From New Latin ammōnium. Equivalent to ammonia + -ium.

Usage

Usually functions as a modifier in chemical names like 'ammonium chloride' or 'ammonium nitrate'.

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