hydrogen
a colorless, odorless, flammable gas that combines chemically with oxygen to form water: the lightest of the known elements. Symbol: H; atomic weight: 1.00797; atomic number: 1; density: 0.0899 grams/liter at 0°C and 760 millimeters pressure.
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Origin of hydrogen
1Words Nearby hydrogen
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2024
How to use hydrogen in a sentence
That’s because plastics are mainly made up of carbon and hydrogen, very widespread elements.
Microplastics are everywhere. Here’s what that means for our health. | Ula Chrobak | February 11, 2021 | Popular-ScienceMaking renewable hydrogen requires making electricity to send a charge through water to split the liquid into hydrogen and oxygen.
A startup using a new tech to make hydrogen extracts cash from Bill Gates’ climate tech fund | Jonathan Shieber | February 9, 2021 | TechCrunchThere, a chemical process breaks the bond between water’s hydrogen and oxygen molecules, forming heat.
The Kora Xenolith Is My Secret Weapon Against the Cold | Wes Siler | February 2, 2021 | Outside OnlineTo begin, the scientists shined X-ray light on hydrogen gas.
Physicists have clocked the shortest time span ever | Maria Temming | January 29, 2021 | Science News For StudentsPolyethylene is a long molecule, in which hydrogen atoms are connected to a carbon backbone that can be thousands of carbon atoms long.
Chemists are reimagining recycling to keep plastics out of landfills | Maria Temming | January 27, 2021 | Science News
Methane (chemical formula CH4) is one of the simplest hydrocarbons, which literally means “containing hydrogen and carbon.”
From that, they extracted the ratio of the number of deuterium atoms to the number of hydrogen atoms.
They found that there are roughly 1,900 hydrogen atoms for each deuterium atom in the water on Comet 67P.
Deuterium is an isotope of hydrogen containing a proton and neutron in its nucleus, while normal hydrogen has only a proton.
Jupiter and its cousins, by contrast, are mostly made of hydrogen and hydrogen compounds.
hydrogen sulphid is easily prepared in the simple apparatus shown in Fig. 30.
A Manual of Clinical Diagnosis | James Campbell ToddIt is allowed to cool, and hydrogen sulphid gas is passed through it for about five minutes.
A Manual of Clinical Diagnosis | James Campbell ToddAmmonia is a compound of nitrogen and hydrogen, but it cannot be formed by the direct union of these gases.
Elements of Agricultural Chemistry | Thomas AndersonOne morning he found that the amount of hydrogen was scarcely perceptible; still there was water in the pit.
Black Diamonds | Mr JkaiThe older workman reassured them; the carbon was much heavier than oxygen, and even thicker than hydrogen.
Black Diamonds | Mr Jkai
British Dictionary definitions for hydrogen
/ (ˈhaɪdrɪdʒən) /
a flammable colourless gas that is the lightest and most abundant element in the universe. It occurs mainly in water and in most organic compounds and is used in the production of ammonia and other chemicals, in the hydrogenation of fats and oils, and in welding. Symbol: H; atomic no: 1; atomic wt: 1.00794; valency: 1; density: 0.08988 kg/m³; melting pt: –259.34°C; boiling pt: –252.87°C: See also deuterium, tritium
(as modifier): hydrogen bomb
Origin of hydrogen
1Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012
Scientific definitions for hydrogen
[ hī′drə-jən ]
The lightest and most abundant element in the universe, normally consisting of one proton and one electron. It occurs in water in combination with oxygen, in most organic compounds, and in small amounts in the atmosphere as a gaseous mixture of its three isotopes (protium, deuterium, and tritium) in the colorless, odorless compound H2. Hydrogen atoms are relatively electropositive and form hydrogen bonds with electronegative atoms. In the Sun and other stars, the conversion of hydrogen into helium by nuclear fusion produces heat and light. Hydrogen is used to make rocket fuel, synthetic ammonia, and methanol, to hydrogenate fats and oils, and to refine petroleum. The development of physical theories of electron orbitals in hydrogen was important in the development of quantum mechanics. Atomic number 1; atomic weight 1.00794; melting point -259.14°C; boiling point -252.8°C; density at 0°C 0.08987 gram per liter; valence 1. See Periodic Table. See Note at oxygen.
The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
Cultural definitions for hydrogen
Notes for hydrogen
Notes for hydrogen
Notes for hydrogen
The New Dictionary of Cultural Literacy, Third Edition Copyright © 2005 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
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