ammonium ion

chemical ion

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June 18, 2026

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The ammonium ion, with the chemical formula NH₄⁺, is formed when an ammonia molecule (NH₃) gains a hydrogen ion. This positively charged ion is known in compounds that share properties with alkali metals. Ammonia itself is a compound of nitrogen and hydrogen, serving as a key ingredient for many nitrogen-based products.123

The ammonium ion plays a role in various applications, notably as a component in fertilizers like ammonium nitrate and ammonium sulfate. It is also involved in the production of explosives and synthetic fibers. In aqueous solutions, ammonia forms ammonium ions and hydroxide ions, creating a basic solution.3

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acid–base reaction
The Brønsted–Lowry definition
…ions (cations), such as the ammonium ion (NH₄⁺), which can be derived by the addition of a proton to a molecular base, in this case ammonia (NH₃). The hydronium ion (H₃O⁺), which is the hydrogen ion in aqueous solution, also belongs to this class. The charge of these ionic acids,…
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…ions (cations), such as the ammonium ion (NH₄⁺), which can be derived by the addition of a proton to a molecular base, in this case ammonia (NH₃). The hydronium ion (H₃O⁺), which is the hydrogen ion in aqueous solution, also belongs to this class. The charge of these ionic acids,…
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soil
Biological phenomena
…by microorganisms and converted into ammonium ions (NH₄⁺) that can be directly absorbed by some plant roots (for example, lowland rice). The ammonium ions are usually converted to nitrite ions (NO₂⁻) by Nitrosomonas bacteria, followed by a second conversion to nitrate (NO₃⁻) by Nitrobacter bacteria. This very mobile form of…
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…by microorganisms and converted into ammonium ions (NH₄⁺) that can be directly absorbed by some plant roots (for example, lowland rice). The ammonium ions are usually converted to nitrite ions (NO₂⁻) by Nitrosomonas bacteria, followed by a second conversion to nitrate (NO₃⁻) by Nitrobacter bacteria. This very mobile form of…
Read More