Table Of Content
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. The Table lists the important properties of molecular hydrogen, H2.
German
It was formerly common for an rather than a to be used as the indefinite article before a word beginning with /h/ in an unstressed syllable, as in "an historian", but use of a is now more usual (see English articles § Indefinite article). Hydrogen is mainly produced by steam methane reforming (SMR), the reaction of water and methane.[103][104] [105] Thus, at high temperatures (1000–1400 K, 700–1100 °C or 1300–2000 °F), steam (water vapor) reacts with methane to yield carbon monoxide and H2. But whencesoever this stinking smoak proceeded, so inflammable it was, that upon the approach of a lighted candle to it, it would readily enough take fire, and burn with a blewish and somewhat greenish flame at the mouth of the viol for a good while together; and that, though with little light, yet with more strength than one would easily suspect. In the alphabets used to write the East Ionic dialect of Greek the letter became superfluous as a result of the disappearance of the aspirate which it represented in that dialect.
A Brief History Of The Letter H
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. Compounds of hydrogen are often called hydrides, a term that is used fairly loosely. 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. The existence of the hydride anion, suggested by Gilbert N. Lewis in 1916 for group 1 and 2 salt-like hydrides, was demonstrated by Moers in 1920 by the electrolysis of molten lithium hydride (LiH), producing a stoichiometric quantity of hydrogen at the anode.[50] For hydrides other than group 1 and 2 metals, the term is quite misleading, considering the low electronegativity of hydrogen.
PASSAGES: Retired Cook County Assistant State's Attorney William H. Hall IV - Windy City Times
PASSAGES: Retired Cook County Assistant State's Attorney William H. Hall IV.
Posted: Thu, 02 May 2024 18:33:45 GMT [source]
Physical and chemical properties
The gas, however, was confused with other flammable gases, such as hydrocarbons and carbon monoxide. In 1766 Henry Cavendish, English chemist and physicist, showed that hydrogen, then called flammable air, phlogiston, or the flammable principle, was distinct from other combustible gases because of its density and the amount of it that evolved from a given amount of acid and metal. In 1781 Cavendish confirmed previous observations that water was formed when hydrogen was burned, and Antoine-Laurent Lavoisier, the father of modern chemistry, coined the French word hydrogène from which the English form is derived. In 1929 Karl Friedrich Bonhoeffer, a German physical chemist, and Paul Harteck, an Austrian chemist, on the basis of earlier theoretical work, showed that ordinary hydrogen is a mixture of two kinds of molecules, ortho-hydrogen and para-hydrogen. Because of the simple structure of hydrogen, its properties can be theoretically calculated relatively easily.
Spanish
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.
symbol for
Thus, in the Old Italic alphabets, the letter Heta of the Euboean alphabet was adopted with its original sound value /h/. Essentially pure para-hydrogen can be produced by bringing the mixture into contact with charcoal at the temperature of liquid hydrogen; this converts all the ortho-hydrogen into para-hydrogen. The ortho-hydrogen, on the other hand, cannot be prepared directly from the mixture because the concentration of para-hydrogen is never less than 25 percent. A more accurate description of the hydrogen atom comes from a purely quantum mechanical treatment that uses the Schrödinger equation, Dirac equation or Feynman path integral formulation to calculate the probability density of the electron around the proton.[31] The most complicated treatments allow for the small effects of special relativity and vacuum polarization.
Pronunciation
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.
Energy carrier
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.
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.
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. Because its molecular weight is lower than that of any other gas, its molecules have a velocity higher than those of any other gas at a given temperature and it diffuses faster than any other gas.
This ion has also been observed in the upper atmosphere of the planet Jupiter. The ion is relatively stable in the environment of outer space due to the low temperature and density. H+3 is one of the most abundant ions in the universe, and it plays a notable role in the chemistry of the interstellar medium.[100] Neutral triatomic hydrogen H3 can exist only in an excited form and is unstable.[101] By contrast, the positive hydrogen molecular ion (H+2) is a rare molecule in the universe. H2 is unreactive compared to diatomic elements such as halogens or oxygen.
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. 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.
The electrolysis of water is a conceptually simple method of producing hydrogen. The uppercase letter for H is H and the lowercase letter for H is h. The letter’s name is "haitch" (/ˈheɪtʃ/), also known as simply "'aitch" (/ˈeɪtʃ/). Sandra Liebenberg, Distinguished Professor and H F Oppenheimer Chair in Human Rights Law, Stellenbosch UniversityThis article is republished from The Conversation under a Creative Commons license. In pre-modern Maltese, h still produces the sound [h] as recorded by Agius de Soldanis (1750) and Mikel Anton Vassalli (1796).
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