Word: hydrogen Part of Speech: noun Etymology: Etymology tree Proto-Indo-European *wed- Proto-Indo-European *-r̥ Proto-Indo-European *wódr̥ Proto-Hellenic *údōr Ancient Greek ῡ̆̔́δωρ (hū̆́dōr) Ancient Greek ὑδρο- (hudro-)lbor. French hydro- Proto-Indo-European *ǵenh₁- Proto-Indo-European *-os Proto-Indo-European *ǵénh₁os Proto-Hellenic *génos Ancient Greek γένος (génos) Proto-Indo-European *-os Proto-Indo-European *-ēs Ancient Greek -ης (-ēs) Ancient Greek -γενής (-genḗs)lbor. French -gène French hydrogènebor. English hydrogen Borrowed from French hydrogène (“hydrogen”), coined by the French chemists Louis-Bernard Guyton de Morveau (1737–1816) and Antoine Lavoisier (1743–1794) from hydro- (prefix meaning ‘water’) + -gène (suffix denoting a producer of something), from the fact that water is produced as a compound when hydrogen is oxidized. * The prefix hydro- is borrowed from Ancient Greek ῠ̔δρο- (hŭdro-), from ῡ̆̔́δωρ (hū̆́dōr, “water”), ultimately from Proto-Indo-European *wed- (“water”). * The suffix -gène is borrowed from Ancient Greek -γενής (-genḗs, suffix meaning ‘born in a certain condition or place’), from γένος (génos, “descendant, offspring; race; etc.”) (ultimately from Proto-Indo-European *ǵenh₁- (“to beget, produce; to give birth”)) + -ης (-ēs, suffix forming some third-declension adjectives). By surface analysis, hydro- (prefix meaning ‘water’) + -gen (suffix denoting a producer of something). Pronunciation: /ˈhaɪdɹəd͡ʒ(ə)n/, [ˈhaɪd͡ʒɹəd͡ʒən] 1. The lightest chemical element (symbol H), with an atomic number of 1 and atomic weight of 1.008. Labels: uncountable Example: Our professor then reminded us that a hydrogen ion is merely a proton, and thus we should think about acid-base theory as we consider this problem further. Example: The ignis fatuus or Jack a lantern, ſo frequently alluded to by poets, is ſuppoſed to originate from the inflammable air, or Hydrogene, given up from moraſſes; […] 2. The lightest chemical element (symbol H), with an atomic number of 1 and atomic weight of 1.008. Labels: countable Example: Each carbon of the ring has one hydrogen attached except for the fourth one, which is bonded to a substituent. Example: Water occupies an intermediate position and shows tendencies both to add and give up hydrogen, which are nearly balanced. Then, in terms of the Lewis theory, a free pair of electrons on one water molecule might be able to exert sufficient force on a hydrogen held by a pair of electrons on another water molecule to bind the two molecules together. 3. Molecular hydrogen (sense 1; symbol H₂), a colourless, odourless and flammable gas at room temperature. Labels: uncountable Example: A large tank of hydrogen constituted most of the bulk of that rocket. Example: [Jacques] Charles was the first to send up a hydrogen balloon, 12 feet in diameter, which rose 3,123 feet, disappeared in the clouds, and fell at the distance of 15 miles. 4. Molecular hydrogen (sense 1; symbol H₂), a colourless, odourless and flammable gas at room temperature. Labels: countable 5. Synonym of protium (“the lightest and most common isotope of hydrogen (sense 1; symbol H, ¹H, or 11H), as contrasted with deuterium and tritium”). Labels: uncountable Example: Both hydrogen and deuterium are present in every glass of water that you drink, but the amount of deuterium is rather small. Example: Hydrogen is generally considered to be electronically the same as deuterium. […] Neutron diffraction experiments by Ferguson, Schindler, Tanaka, and Morita (ref. 4) revealed that, near 50K, some hydrogen had moved from interstitial octahedral sites (0, 0, 1/2; 1/2, 0, 0; …) of the palladium lattice to the tetrahedral sites (1/4, 1/4, 1/4; 3/4, 3/4; …) (O-T transitions).