Under the Brønsted–Lowry acid–base theory, acids are proton donors, while bases are proton acceptors. See the history of Polish orthography article on Wikipedia for more, and h for development of the glyph itself. See the Kashubian alphabet article on Wikipedia for more, and h for development of the glyph itself.
Spanish
The term "hydride" suggests that the H atom has acquired a negative or anionic character, denoted H−, and is used when hydrogen forms a compound with a more electropositive element. 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.
Water electrolysis
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The thermodynamic basis of this low reactivity is the very strong H–H bond, with a bond dissociation energy of 435.7 kJ/mol.[26] The kinetic basis of the low reactivity is the nonpolar nature of H2 and its weak polarizability. It spontaneously reacts with chlorine and fluorine to form hydrogen chloride and hydrogen fluoride, respectively.[27] The reactivity of H2 is strongly affected by the presence of metal catalysts. Thus, while mixtures of H2 with O2 or air combust readily when heated to at least 500 °C by a spark or flame, they do not react at room temperature in the absence of a catalyst.
Derived terms
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'). The spelling reflects an earlier pronunciation of the sound /h/. 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⟩.
Pronunciation
The cursive Latin form resembled a stylized version of the modern minuscule h, as did the uncial form. Both of these forms result from writing the letter without taking the pen from the paper, the right-hand vertical bar being thus foreshortened and the horizontal stroke rounded. From these came the Carolingian form as well as the modern minuscule h. It consists of two protons and two electrons held together by electrostatic forces. Like atomic hydrogen, the assemblage can exist in a number of energy levels. Hydrogen is transparent to visible light, to infrared light, and to ultraviolet light to wavelengths below 1800 Å.
Electron energy levels
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. The gas, however, was confused with other flammable gases, such as hydrocarbons and carbon monoxide.
In most dialects of Polish, both ⟨h⟩ and the digraph ⟨ch⟩ always represent /x/. In Ukrainian and Belarusian, when written in the Latin alphabet, ⟨h⟩ is also commonly used for /ɦ/, which is otherwise written with the Cyrillic letter ⟨г⟩. We value customer satisfaction and offer store credit and exchange policy for eligible products.Returns or exchanges will only be accepted for unused, unwashed, and undamaged items, with all original tags and packaging intact.Prior authorization is required for all returns or exchanges. Customers must contact our customer service team for return instructions within seven (5) days of receiving the order.Shipping costs for returns or exchanges are the responsibility of the customer, unless the return is due to our error or product defects.Store Credit for returned items will be issued after we receive and inspect the returned merchandise. Steam reforming is also used for the industrial preparation of ammonia. From Gaj's Latin alphabet h, from Czech alphabet h, from Latin h.
It was accordingly put to a new use to indicate the open long e which had arisen through alteration of the primitive Greek long a. In a few inscriptions from Thera, Naxos, and several other localities the letter was used with syllabic value; that is, it included he, thus showing its old consonantal and its new vocalic value at the same time. Eventually, as a result of the spread of the Ionic alphabet, its use for the long vowel e or η became general throughout Greece, while its consonantal value as the aspirate h passed from the western Greek alphabets into the Etruscan alphabets and then into the Latin and other alphabets of ancient Italy. In the Romance languages the sound has largely disappeared, but the letter is still extensively used, partly with only etymological value, (e.g., French homme), partly with fancied etymological value (e.g., French haut from Latin altus, with h through the influence of hoh, the Old High German word of the same meaning), partly with special orthographical functions.
Even though it is often said that there are more known compounds of carbon than of any other element, the fact is that, since hydrogen is contained in almost all carbon compounds and also forms a multitude of compounds with all other elements (except some of the noble gases), it is possible that hydrogen compounds are more numerous. 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. This ion has also been observed in the upper atmosphere of the planet Jupiter.
The initial h often disappears in unaccented syllables (e.g., “What did he say?”). 'H' is also used in many spelling systems in digraphs and trigraphs, such as 'ch', which represents /tʃ/ in Spanish, Galician, and Old Portuguese; /ʃ/ in French and modern Portuguese; /k/ in Italian and French. Oxidation of hydrogen removes its electron and gives H+, which contains no electrons and a nucleus which is usually composed of one proton.
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.
This is because ⟨j⟩ and ⟨v⟩ used to be considered variants of ⟨i⟩ and ⟨u⟩ respectively. ⟨h⟩ also appears in the digraph ⟨ch⟩, which represents /tʃ/ in Spanish and northern Portugal, and /ʃ/ in varieties that have merged both sounds (the latter originally represented by ⟨x⟩ instead), such as most of the Portuguese language and some Spanish dialects, prominently Chilean Spanish. H2 is unreactive compared to diatomic elements such as halogens or oxygen.
These include low density, low viscosity, and the highest specific heat and thermal conductivity of all gases. Many metals such as zirconium undergo a similar reaction with water leading to the production of hydrogen. 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. 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). Note that it represents the sound of IPA [x] (like German machen, ach), not (as in most other alphabets based on the Latin script) the sound of IPA [h].
Hydrogen-lifted airships were used as observation platforms and bombers during the war. See the Silesian language article on Wikipedia for more, and h for development of the glyph itself. In English the initial h is pronounced in words of Germanic origin (e.g., hunt, hook); in some words of Romance origin, the h remains unpronounced (e.g., heir, honour), but in others it has been restored (e.g., humble, humour).
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. In Basque, during the 20th century it was not used in the orthography of the Basque dialects in Spain but it marked an aspiration in the North-Eastern dialects.
For example, in Italian h is used in combination with c or g to indicate the hard sound before a front vowel (e.g., chi, ghetto). The Greek Eta 'Η' in archaic Greek alphabets, before coming to represent a long vowel, /ɛː/, still represented a similar sound, the voiceless glottal fricative /h/. In this context, the letter eta is also known as Heta to underline this fact. Thus, in the Old Italic alphabets, the letter Heta of the Euboean alphabet was adopted with its original sound value /h/.
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