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Consequently, kinetic energy is distributed faster through hydrogen than through any other gas; it has, for example, the greatest heat conductivity. Elementary hydrogen finds its principal industrial application in the manufacture of ammonia (a compound of hydrogen and nitrogen, NH3) and in the hydrogenation of carbon monoxide and organic compounds. Hydrogen is commonly used in power stations as a coolant in generators due to a number of favorable properties that are a direct result of its light diatomic molecules. These include low density, low viscosity, and the highest specific heat and thermal conductivity of all gases.
Word History and Origins
Hydrogen is a chemical element; it has symbol H and atomic number 1. It is the lightest element and, at standard conditions, is a gas of diatomic molecules with the formula H2, sometimes called dihydrogen,[11] but more commonly called hydrogen gas, molecular hydrogen or simply hydrogen. It is colorless, odorless, tasteless,[12] non-toxic, and highly combustible. Constituting approximately 75% of all normal matter, hydrogen is the most abundant chemical substance in the universe.[13][note 1] Stars, including the Sun, primarily consist of hydrogen in a plasma state, while on Earth, hydrogen is found in water, organic compounds, and other molecular forms. The most common isotope of hydrogen (symbol 1H) consists of one proton, one electron, and no neutrons. Paracelsus, physician and alchemist, in the 16th century unknowingly experimented with hydrogen when he found that a flammable gas was evolved when a metal was dissolved in acid.
Students use practical life skills at Morgan County 4-H competition - The Hartselle Enquirer - Hartselle Enquirer
Students use practical life skills at Morgan County 4-H competition - The Hartselle Enquirer.
Posted: Thu, 02 May 2024 14:26:43 GMT [source]
Related Words
Hence hydrogen is often used as a theoretical model for more complex atoms, and the results are applied qualitatively to other atoms. These differ in the magnetic interactions of the protons due to the spinning motions of the protons. In ortho-hydrogen, the spins of both protons are aligned in the same direction—that is, they are parallel. In para-hydrogen, the spins are aligned in opposite directions and are therefore antiparallel. The relationship of spin alignments determines the magnetic properties of the atoms. Normally, transformations of one type into the other (i.e., conversions between ortho and para molecules) do not occur and ortho-hydrogen and para-hydrogen can be regarded as two distinct modifications of hydrogen.
Role in quantum theory
During the standardization of Basque in the 1970s, the compromise was reached that h would be accepted if it were the first consonant in a syllable. Hence, herri ("people") and etorri ("to come") were accepted instead of erri (Biscayan) and ethorri (Souletin). For the dialects lacking the aspiration, this meant a complication added to the standardized spelling.
In lithium aluminium hydride, the [AlH4]− anion carries hydridic centers firmly attached to the Al(III). Throughout the universe, hydrogen is mostly found in the atomic and plasma states, with properties quite distinct from those of molecular hydrogen. As a plasma, hydrogen's electron and proton are not bound together, resulting in very high electrical conductivity and high emissivity (producing the light from the Sun and other stars). The charged particles are highly influenced by magnetic and electric fields.
Historically, hydrogen gas was first produced artificially in the early 16th century through the reaction of acids with metals. Henry Cavendish, between 1766 and 1781, identified hydrogen gas as a distinct substance[16] and discovered its property of producing water when burned—hence its name derived from the Greek "water-former". Although hydrogen is the most abundant element in the universe (three times as abundant as helium, the next most widely occurring element), it makes up only about 0.14 percent of Earth’s crust by weight. It occurs, however, in vast quantities as part of the water in oceans, ice packs, rivers, lakes, and the atmosphere. As part of innumerable carbon compounds, hydrogen is present in all animal and vegetable tissue and in petroleum.
Energy carrier
Improving protections for H-2A workers in the United States - FreshPlaza.com
Improving protections for H-2A workers in the United States.
Posted: Thu, 02 May 2024 12:05:06 GMT [source]
The original Semitic letter Heth most likely represented the voiceless pharyngeal fricative (ħ). The first non-stop transatlantic crossing was made by the British airship R34 in 1919. Regular passenger service resumed in the 1920s and the discovery of helium reserves in the United States promised increased safety, but the U.S. government refused to sell the gas for this purpose. Therefore, H2 was used in the Hindenburg airship, which was destroyed in a midair fire over New Jersey on 6 May 1937.[8] The incident was broadcast live on radio and filmed.
French
From Gaj's Latin alphabet h, from Czech alphabet h, from Latin h. Pronunciation as /xə/ is initial Slovene (phoneme plus a fill vowel) and the second pronunciation is probably taken from German h. The Finnish orthography using the Latin script was based on those of Swedish, German and Latin, and was first used in the mid-16th century. See the Wikipedia article on Finnish for more information, and h for information on the development of the glyph itself. The carbon may be sold as a manufacturing feedstock or fuel, or landfilled.
Meaning of H, h in English
Ignition of leaking hydrogen is widely assumed to be the cause, but later investigations pointed to the ignition of the aluminized fabric coating by static electricity. But the damage to hydrogen's reputation as a lifting gas was already done and commercial hydrogen airship travel ceased. Hydrogen is still used, in preference to non-flammable but more expensive helium, as a lifting gas for weather balloons. In Metelko alphabet, the phoneme was written by two different letters whether it was pronounced as velar /x/ or glottal /h/, a distinction irrelevant to nowadays standard and the distinction was also not used by all writers. Phoneme /h/ was written with 〈h〉, while /x/ was written with a yet to be encoded character .
The extremely low melting and boiling points result from weak forces of attraction between the molecules. The existence of these weak intermolecular forces is also revealed by the fact that, when hydrogen gas expands from high to low pressure at room temperature, its temperature rises, whereas the temperature of most other gases falls. According to thermodynamic principles, this implies that repulsive forces exceed attractive forces between hydrogen molecules at room temperature—otherwise, the expansion would cool the hydrogen. In fact, at −68.6° C attractive forces predominate, and hydrogen, therefore, cools upon being allowed to expand below that temperature. The cooling effect becomes so pronounced at temperatures below that of liquid nitrogen (−196° C) that the effect is utilized to achieve the liquefaction temperature of hydrogen gas itself. A molecular form called protonated molecular hydrogen (H+3) is found in the interstellar medium, where it is generated by ionization of molecular hydrogen from cosmic rays.
The early contemporary variant was first found in the dialect of lsien tal-bliet (“tongues of the cities”, referring to the cities around the Grand Harbour according to Vassalli) which eventually superceded the increasingly archaic [h] sound in the neighborhing areas.
The two forms may, however, interconvert under certain conditions. Equilibrium between the two forms can be established in several ways. One of these is by the introduction of catalysts (such as activated charcoal or various paramagnetic substances); another method is to apply an electrical discharge to the gas or to heat it to a high temperature. In Spanish and Portuguese, ⟨h⟩ is a silent letter with no pronunciation, as in hijo [ˈixo] ('son') and húngaro [ˈũɡaɾu] ('Hungarian'). In words where the ⟨h⟩ is derived from a Latin /f/, it is still sometimes pronounced with the value [h] in some regions of Andalusia, Extremadura, Canarias, Cantabria, and the Americas. Some words beginning with [je] or [we], such as hielo, 'ice' and huevo, 'egg', were given an initial ⟨h⟩ to avoid confusion between their initial semivowels and the consonants ⟨j⟩ and ⟨v⟩.
In the quantum mechanical treatment, the electron in a ground state hydrogen atom has no angular momentum at all—illustrating how the "planetary orbit" differs from electron motion. In the early Greek alphabets a form with three horizontal bars and the simpler form H were both widely distributed. In Etruscan the prevailing form was similar to the early Greek form, and the same or a similar form occurs in very early Latin inscriptions, but the form H came into general use in Latin, either from the Chalcidic Greek alphabet of Cumae or from some other source. The cursive Latin form resembled a stylized version of the modern minuscule h, as did the uncial form.
Some languages, including Czech, Slovak, Hungarian, Finnish, and Estonian use ⟨h⟩ as a breathy voiced glottal fricative [ɦ], often as an allophone of otherwise voiceless /h/ in a voiced environment. Many metals such as zirconium undergo a similar reaction with water leading to the production of hydrogen. Hydrogen-lifted airships were used as observation platforms and bombers during the war. The letter H/h (like F/f, and O/o representing [o], [oː] instead of [uə̯]) is found only in words of foreign origin (borrowings).
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