deuterium

American  

[doo-teer-ee-uhm, dyoo-] / duˈtɪər i əm, dju- /

noun

Chemistry.

1. an isotope of hydrogen, having twice the mass of ordinary hydrogen; heavy hydrogen. 2 H, D; 2.01; 1.

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deuterium British  

/ djuːˈtɪərɪəm /

noun

1. a stable isotope of hydrogen, occurring in natural hydrogen (156 parts per million) and in heavy water: used as a tracer in chemistry and biology. Symbol: D or ²H; atomic no: 1; atomic wt: 2.014; boiling pt: –249.7°C

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deuterium Scientific  

/ do̅o̅-tîr′ē-əm /

1. An isotope of hydrogen whose nucleus has one proton and one neutron and whose atomic mass is 2. Deuterium is used widely as a tracer for analyzing chemical reactions, and it combines with oxygen to form heavy water.

2. Also called heavy hydrogen

3. See Note at heavy water

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Etymology

Origin of deuterium

1933; < Greek deúter ( os ) second ( see deutero-) + -ium

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Compare meaning

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

• deuterium vs. hydrogen

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Example Sentences

See Examples For:

deuterium

But some forms of water contain deuterium, an isotope of hydrogen that includes both a proton and a neutron.

From Science Daily ● May 8, 2026

First-generation reactors will almost certainly be fueled by the hydrogen isotopes deuterium and tritium.

From The Wall Street Journal ● Dec. 28, 2025

They also studied its deuterium counterpart, D3S, which showed a smaller gap of about 44 meV.

From Science Daily ● Dec. 21, 2025

A good thing to note is that deuterium, a stable isotope of hydrogen, is much less expensive and can be found in seawater.

From Los Angeles Times ● Sep. 15, 2024

His discovery was a triumph of scientific deduction, for the neutron, which gives deuterium its additional weight, was not discovered until many months after he identified the isotope itself.

From "Big Science" by Michael Hiltzik

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