deuterium

American  

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

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

Compare meaning

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

• deuterium vs. hydrogen

Example Sentences

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

From The Wall Street Journal • Dec. 28, 2025

Researchers, working on nuclear fusion, are fusing tritium and deuterium together to maximize the amount of energy created in one small area.

From Los Angeles Times • Sep. 15, 2024

Cancerous cells exhibited a similar but not quite as strong shortage in deuterium.

From Science Daily • May 6, 2024

One limitation is that JT-60SA will only use hydrogen and its isotope deuterium in its experiments, not tritium—a third form of hydrogen that is expensive, scarce, and radioactive.

From Science Magazine • Oct. 31, 2023

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