hy·​dro·​gen | \ ˈhī-drə-jən How to pronounce hydrogen (audio) , -dər- \

Definition of hydrogen

: a nonmetallic gaseous chemical element with atomic number 1 that is the simplest and lightest of the elements and that is used especially in the processing of fossil fuels and the synthesis of ammonia — see Chemical Elements Table — compare deuterium, tritium

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Other Words from hydrogen

hydrogenous \ hī-​ˈdrä-​jə-​nəs How to pronounce hydrogenous (audio) \ adjective

Examples of hydrogen in a Sentence

Recent Examples on the Web The Pioneer plaque gives a hint in the form of a basic diagram of a hydrogen atom, the magnetic polarity of which flips at regular intervals, with a frequency of 1,420MHz. The Economist, "How to talk to aliens," 28 Nov. 2019 By electrolysis -- sending an electric current through water to split hydrogen atoms from oxygen. William Wilkes, Washington Post, "How ‘Green Hydrogen’ Could Make ‘Green Steel’ Real," 23 Nov. 2019 Methylation occurs when methyl groups—clusters of hydrogen atoms surrounding a carbon atom—attach to the DNA and prevent their expression. Nick Heil, Outside Online, "This Company Will Tell You How Well You're Aging," 11 Nov. 2019 The robots could then use hydrogen atoms from interstellar dust to power themselves. Fox News, "Trillions of alien ‘robot probes’ may be in space but are too small for NASA to spot, shock paper claims," 22 Oct. 2019 This caused a small hydrogen leak that began to build up, forming a pocket of gas within the airship that failed to dissipate. Eric Larsen, USA TODAY, "Last survivor of Hindenburg crash dies at age 90," 17 Nov. 2019 Since then, researchers have detected organic molecules and hydrogen in the jets—potential food for microbes—making Enceladus one of the top destinations in the search for life elsewhere in the Solar System. Adam Mann, Science | AAAS, "How Enceladus got its water-spewing tiger stripes," 13 Nov. 2019 Scientists believe that in this fraction of a second, the star was able to build up enough energy to blast its hydrogen layer into space. Jennifer Leman, Popular Mechanics, "NASA Telescope Spots Massive, Trippy Thermonuclear Blast," 12 Nov. 2019 So even for the simplest ion (hydrogen with an electron removed), the g-factor cannot be calculated with sufficient accuracy to truly test quantum electrodynamics. Chris Lee, Ars Technica, "Quantum mechanics gets stern challenge from single silicon ion," 8 Nov. 2019

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'hydrogen.' 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 hydrogen

1788, in the meaning defined above

History and Etymology for hydrogen

French hydrogène, from hydr- + -gène -gen; from the fact that water is generated by its combustion

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Time Traveler for hydrogen

Time Traveler

The first known use of hydrogen was in 1788

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Statistics for hydrogen

Last Updated

4 Dec 2019

Cite this Entry

“Hydrogen.” The Merriam-Webster.com Dictionary, Merriam-Webster Inc., https://www.merriam-webster.com/dictionary/hydrogen. Accessed 7 December 2019.

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More Definitions for hydrogen


How to pronounce hydrogen (audio)

English Language Learners Definition of hydrogen

: a chemical element that has no color or smell and that is the simplest, lightest, and most common element


hy·​dro·​gen | \ ˈhī-drə-jən How to pronounce hydrogen (audio) \

Kids Definition of hydrogen

: a colorless, odorless, and tasteless flammable gas that is the lightest of the chemical elements


hy·​dro·​gen | \ ˈhī-drə-jən How to pronounce hydrogen (audio) \

Medical Definition of hydrogen

: a nonmetallic element that is the simplest and lightest of the elements and that is normally a colorless odorless highly flammable diatomic gas symbol H — see deuterium, tritium Chemical Elements Table

Other Words from hydrogen

hydrogenous \ hī-​ˈdräj-​ə-​nəs How to pronounce hydrogenous (audio) \ adjective

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More from Merriam-Webster on hydrogen

Spanish Central: Translation of hydrogen

Nglish: Translation of hydrogen for Spanish Speakers

Britannica English: Translation of hydrogen for Arabic Speakers

Britannica.com: Encyclopedia article about hydrogen

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