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

Scientists use deuterium levels as a kind of chemical fingerprint that reveals the conditions present when celestial objects formed.

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

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

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

The neutron and deuterium were both discoveries from that miraculous year of 1932, when nuclear physics gave up some of its greatest secrets.

From "Big Science" by Michael Hiltzik