Hydrogen definition

hīdrə-jən
The definition of hydrogen is a gaseous element that has no color or odor and is flammable.
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A colorless, highly flammable element, that occurs as a diatomic molecule, H2 , the lightest of all gases and the most abundant element in the universe, used in the production of synthetic ammonia and methanol, in petroleum refining, in the hydrogenation of organic materials, as a reducing atmosphere, in oxyhydrogen torches, in cryogenic research, and in rocket fuels. Atomic number 1; atomic weight 1.00794; melting point −259.1°C; boiling point −252.8°C; density at 0°C 0.08988 gram per liter; valence 1.
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The lightest chemical element (symbol H) with an atomic number of 1 and atomic weight of 1.00794.
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An atom of the element.
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Hydrogen is the most plentiful element in the universe.
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An atom of hydrogen is made up of two subatomic particles, one electron and one proton.
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Tritium is radioactive and is used in the construction and operation of nuclear weapons.
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Hydrogen gas was the first fuel used in inflatable aircrafts and Zeppelins, such as the Hindenburg which exploded in 1937.
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An atom of hydrogen is the smallest of all elements that exist.
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Hydrogen exists in three forms - hydrogen, deuterium, and tritium.
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The combustion of hydrogen is very clean and has little impact on the environment. The byproduct of the combustion of hydrogen and oxygen is water vapor.
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Hydrogen is a perfect liquid for cryogenic freezing.

An example of hydrogen is one of the elements in water.

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A flammable, colorless, odorless, gaseous chemical element, the lightest of all known substances: symbol, H; at. no. 1
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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.
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Molecular hydrogen (H2), a colourless, odourless and flammable gas at room temperature.
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A sample of the element.
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Other Word Forms

Noun

Singular:
hydrogen
Plural:
hydrogens

Origin of hydrogen

  • French hydrogène Greek hudro- hydro- French -gène -gen

    From American Heritage Dictionary of the English Language, 5th Edition

  • From French hydrogène, coined by Louis-Bernard Guyton de Morveau, from Ancient Greek ὕδωρ (hudōr, “water”) + γεννάω (gennaō, “I bring forth”).

    From Wiktionary