deu·​te·​ri·​um | \ dü-ˈtir-ē-əm How to pronounce deuterium (audio) also dyü- \

Definition of deuterium

: an isotope of hydrogen that has one proton and one neutron in its nucleus and that has twice the mass of ordinary hydrogen symbol D

called also heavy hydrogen

Examples of deuterium in a Sentence

Recent Examples on the Web The result lined up perfectly with Desch’s deuterium evidence. Paul Voosen, Science | AAAS, 23 Mar. 2021 The feather will be assayed for deuterium to add to a study of hydrogen isotopes and duck movements. Paul A. Smith, Milwaukee Journal Sentinel, 22 May 2021 After the dust settles, the Universe becomes about 75% hydrogen, 25% helium-4, 0.01% each helium-3 and deuterium, and about 0.0000001% lithium-7. Ethan Siegel, Forbes, 6 May 2021 The tech can also work for hydrogen isotope fuels like deuterium-tritium, TAE says. Caroline Delbert, Popular Mechanics, 8 Apr. 2021 Scientists also know how quickly standard hydrogen is escaping Mars’ atmosphere today, while a heavier form of it called deuterium stays behind. Theresa Machemer, Smithsonian Magazine, 19 Mar. 2021 Thus, a relative dearth of deuterium in the atmosphere today suggests that less water may have been lost in this way than was thought. Jonathan O'callaghan, Scientific American, 18 Mar. 2021 One of the keys to coming up with the answer to this puzzling anomaly is the existence of deuterium, which is a version of hydrogen with both a proton and a neutron, instead of a single proton as is the case with most hydrogen atoms. Mike Wehner, BGR, 16 Mar. 2021 The experiment aims to show that fusion of the deuterium and tritium nuclei can produce more energy than generating the plasma consumes. Adrian Cho, Science | AAAS, 19 Feb. 2021

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'deuterium.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

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First Known Use of deuterium

1933, in the meaning defined above

History and Etymology for deuterium

New Latin, from Greek deuteros second

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Time Traveler for deuterium

Time Traveler

The first known use of deuterium was in 1933

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Statistics for deuterium

Last Updated

12 Jun 2021

Cite this Entry

“Deuterium.” Dictionary, Merriam-Webster, Accessed 12 Jun. 2021.

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More Definitions for deuterium


deu·​te·​ri·​um | \ d(y)ü-ˈtir-ē-əm How to pronounce deuterium (audio) \

Medical Definition of deuterium

: an isotope of hydrogen that has one proton and one neutron in its nucleus and that has twice the mass of ordinary hydrogen

called also heavy hydrogen

More from Merriam-Webster on deuterium Encyclopedia article about deuterium


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