Adjacent Words

Hydrogen definitions

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Webster's 1828 Dictionary

HY'DROGEN, n. [Gr. water, and to generate; so called as being considered the generator of water.]
In Chimistry, a gas which constitutes one of the elements of water, of which it is said by Lavoisier to form fifteen parts in a hundred; but according to Berzelius and Dulong, hydrogen gas is 11.1 parts in a hundred, and oxyGenesis 88.9. Hydrogen gas is an aeriform fluid,the lightest body known, and though extremely inflammable itself,it extinguishes burning bodies, and is fatal to animal life. Its specific gravity is 0.0694, that of air being 1.00. In consequence of its extreme lightness, it is employed for filling air balloons.

WordNet (r) 3.0 (2005)

n
1: a nonmetallic univalent element that is normally a colorless and odorless highly flammable diatomic gas; the simplest and lightest and most abundant element in the universe [syn: hydrogen, H, atomic number 1]

Merriam Webster's

noun Etymology: French hydrogène, from hydr- + -gène -gen; from the fact that water is generated by its combustion Date: 1788 a nonmetallic element that is the simplest and lightest of the elements, is normally a colorless odorless highly flammable diatomic gas, and is used especially in synthesis — see element table; compare deuterium, tritium • hydrogenous adjective

Dictionary of the Elements

hydrogen
Symbol: H
Atomic number: 1
Atomic weight: 1.0079
Colourless, odourless gaseous chemical element. Lightest and most abundant element in the universe. Present in water and in all organic compounds. Chemically reacts with most elements. Discovered by Henry Cavendish in 1776.

Oxford Reference Dictionary

n. Chem. a colourless gaseous element, without taste or odour, the lightest of the elements and occurring in water and all organic compounds. Usage: Symb.: H. Phrases and idioms: hydrogen bomb an immensely powerful bomb utilizing the explosive fusion of hydrogen nuclei: also called H-BOMB. hydrogen bond a weak electrostatic interaction between an electronegative atom and a hydrogen atom bonded to a different electronegative atom. hydrogen peroxide a colourless viscous unstable liquid with strong oxidizing properties. Usage: Chem. formula: H2O2 hydrogen sulphide a colourless poisonous gas with a disagreeable smell, formed by rotting animal matter. Usage: Chem. formula: H2S Derivatives: hydrogenous adj. Etymology: F hydrogène (as HYDRO-, -GEN)

Webster's 1913 Dictionary

Hydrogen Hy"dro*gen, n. [Hydro-, 1 + -gen: cf. F. hydrog[`e]ne. So called because water is generated by its combustion. See Hydra.] (Chem.) A gaseous element, colorless, tasteless, and odorless, the lightest known substance, being fourteen and a half times lighter than air (hence its use in filling balloons), and over eleven thousand times lighter than water. It is very abundant, being an ingredient of water and of many other substances, especially those of animal or vegetable origin. It may by produced in many ways, but is chiefly obtained by the action of acids (as sulphuric) on metals, as zinc, iron, etc. It is very inflammable, and is an ingredient of coal gas and water gas. It is standard of chemical equivalents or combining weights, and also of valence, being the typical monad. Symbol H. Atomic weight 1.

Collin's Cobuild Dictionary

Hydrogen is a colourless gas that is the lightest and commonest element in the universe.

Soule's Dictionary of English Synonyms

n. (Chem.) Inflammable air, phlogiston.