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The most common isotope of hydrogen, termed protium name rarely used, symbol 1 Hhas one proton and no neutrons. The universal emergence of atomic hydrogen first occurred during the recombination epoch. At standard temperature and pressurehydrogen is a colorlessodorlesstastelessnon-toxic, nonmetallichighly combustible diatomic gas with the molecular formula H 2. Since hydrogen readily forms covalent compounds with most nonmetallic elements, most of the hydrogen on Earth exists in molecular forms such as water or organic compounds.

Hydrogen plays a particularly important role in acid—base reactions because most acid-base reactions involve the exchange of protons between soluble molecules. In ionic compoundshydrogen can take the form of a negative charge i.

The hydrogen cation is written as though composed of a bare proton, but in reality, hydrogen cations in ionic compounds are always more complex. Hydrogen gas was first artificially produced in the early 16th century by the reaction of acids on metals.

In —81, Henry Cavendish was the first to recognize that hydrogen gas was a discrete substance, [11] and that it produces water when burned, the property for which it was later named: Industrial production is mainly from steam reforming natural gas, and less often from more energy-intensive methods such as the electrolysis of water.

Hydrogen is a concern in metallurgy as it can embrittle many metals, [13] complicating the design of pipelines and storage tanks. The explosive reactions may be triggered by spark, heat, or sunlight. The detection of a burning hydrogen leak may require a flame detector ; such leaks can be very dangerous.

Hydrogen flames in other conditions are blue, resembling blue natural gas flames. The destruction of the Hindenburg airship was a notorious example of hydrogen combustion and the cause is still debated.

The visible orange flames in that incident were the result of a rich mixture of hydrogen to oxygen combined with carbon compounds from the airship skin.

H 2 reacts with every oxidizing element. Hydrogen can react spontaneously and violently at room temperature with chlorine and fluorine to form the corresponding hydrogen halides, hydrogen chloride and hydrogen fluoridewhich are also potentially dangerous acids.

The energy levels of hydrogen can be calculated fairly accurately using the Bohr model of the atom, which conceptualizes the electron as "orbiting" the proton in analogy to the Earth's orbit of the Sun. However, the atomic electron and proton are held together by electromagnetic forcewhile planets and celestial objects are held by gravity. Because of the discretization of angular momentum postulated in early quantum mechanics by Bohr, the electron in the Bohr model can only occupy certain allowed distances from the proton, and therefore only certain allowed energies.

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. There exist two different spin isomers of hydrogen diatomic molecules that differ by the relative spin of their nuclei.

At very low temperatures, the equilibrium state is composed almost exclusively of the para form. The liquid and gas phase thermal properties of pure parahydrogen differ significantly from those of the normal form because of differences in rotational heat capacities, as discussed more fully in spin isomers of hydrogen. The uncatalyzed interconversion between para and ortho H 2 increases with increasing temperature; thus rapidly condensed H 2 contains large quantities of the high-energy ortho form that converts to the para form very slowly.

Catalysts for the ortho-para interconversion, such as ferric oxideactivated carbonplatinized asbestos, rare earth metals, uranium compounds, chromic oxideor some nickel [30] compounds, are used during hydrogen cooling.

While H 2 is not very reactive under standard conditions, it does form compounds with most elements. Hydrogen can form compounds with elements that are more electronegativesuch as halogens e.

These compounds are often known as hydrides. Hydrogen forms a vast array of compounds with carbon called the hydrocarbonsand an even vaster array with heteroatoms that, because of their general association with living things, are called organic compounds.

However, most of them also contain hydrogen, and because it is the carbon-hydrogen bond which gives this class of compounds most of its particular chemical characteristics, carbon-hydrogen bonds are required in some definitions of the word "organic" in chemistry.

Compounds of hydrogen are often called hydridesa term that is used fairly loosely. The existence of the hydride anionsuggested by Gilbert N. Lewis in for group 1 and 2 salt-like hydrides, was demonstrated by Moers in by the electrolysis of molten lithium hydride LiHproducing a stoichiometry quantity of hydrogen at the anode. An exception in group 2 hydrides is BeH 2which is polymeric.

Although hydrides can be formed with almost all main-group elements, the number and combination of possible compounds varies widely; for example, more than binary borane hydrides are known, but only one binary aluminium hydride. In inorganic chemistryhydrides can also serve as bridging ligands that link two metal centers in a coordination complex.

This function is particularly common in group 13 elementsespecially in boranes boron hydrides and aluminium complexes, as well as in clustered carboranes. This species is central to discussion of acids.

Under the Bronsted-Lowry theoryacids are proton donors, while bases are proton acceptors. Except at the high temperatures associated with plasmas, such protons cannot be removed from the electron clouds of atoms and molecules, and will remain attached to them.

Hydrogen has three naturally occurring isotopes, denoted 1 H2 H and 3 H. Other, highly unstable nuclei 4 H to 7 H have been synthesized in the laboratory but not observed in nature. Hydrogen is the only element that has different names for its isotopes in common use today. During the early study of radioactivity, various heavy radioactive isotopes were given their own names, but such names are no longer used, except for deuterium and tritium.

The symbols D and T instead of 2 H and 3 H are sometimes used for deuterium and tritium, but the corresponding symbol for protium, P, is already in use for phosphorus and thus is not available for protium. The exotic atom muonium symbol Mucomposed of an antimuon and an electronis also sometimes considered as a light radioisotope of hydrogen, due to the mass difference between the antimuon and the electron.

InRobert Boyle discovered and described the reaction between iron filings and dilute acidswhich results in the production of hydrogen gas. He speculated that "inflammable air" was in fact identical to the hypothetical substance called " phlogiston " [64] [65] and further finding in that the gas produces water when burned.

He is usually given credit for the discovery of hydrogen as an element. Lavoisier produced hydrogen for his experiments on mass conservation by reacting a flux of steam with metallic iron through an incandescent iron tube heated in a fire.

Anaerobic oxidation of iron by the protons of water at high temperature can be schematically represented by the set of following reactions:. Many metals such as zirconium undergo a similar reaction with water leading to the production of hydrogen. Hydrogen was liquefied for the first time by James Dewar in by using regenerative cooling and his invention, the vacuum flask.

Edward Daniel Clarke invented the hydrogen gas blowpipe in The first hydrogen-filled balloon was invented by Jacques Charles in Hydrogen-lifted airships were used as observation platforms and bombers during the war.

The first non-stop transatlantic crossing was made by the British airship R34 in Regular passenger service resumed in the s and the discovery of helium reserves in the United States promised increased safety, but the U. Therefore, H 2 was used in the Hindenburg airship, which was destroyed in a midair fire over New Jersey on 6 May 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. The nickel hydrogen battery was used for the first time in aboard the U. Navy's Navigation technology satellite-2 NTS In the dark part of its orbit, the Hubble Space Telescope is also powered by nickel-hydrogen batteries, which were finally replaced in May[71] more than 19 years after launch and 13 years beyond their design life.

Because of its simple atomic structure, consisting only of a proton and an electron, the hydrogen atomtogether with the spectrum of light produced from it or absorbed by it, has been central to the development of the theory of atomic structure. One of the first quantum effects to be explicitly noticed but not understood at the time was a Maxwell observation involving hydrogen, half a century before full quantum mechanical theory arrived.

Maxwell observed that the specific heat capacity of H 2 unaccountably departs from that of a diatomic gas below room temperature and begins to increasingly resemble that of a monatomic gas at cryogenic temperatures. According to quantum theory, this behavior arises from the spacing of the quantized rotational energy levels, which are particularly wide-spaced in H 2 because of its low mass. These widely spaced levels inhibit equal partition of heat energy into rotational motion in hydrogen at low temperatures.

Diatomic gases composed of heavier atoms do not have such widely spaced levels and do not exhibit the same effect. Antihydrogen H is the antimatter counterpart to hydrogen.

It consists hedging equity options an antiproton with a positron.

Antihydrogen is the only type of antimatter atom to have h&r thumb hole stocks for sale produced as of Most of the mass of the universe, however, is not in the form of chemical-element type matter, but rather is postulated to occur as yet-undetected forms of mass such as dark matter and dark energy. Molecular clouds of H 2 are associated with star formation. Hydrogen plays a vital role in powering stars through the proton-proton reaction and the CNO cycle nuclear fusion.

Throughout the universe, hydrogen is mostly found in the atomic and plasma states, with properties quite different 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. For example, in the solar wind they interact with the Earth's magnetosphere giving rise to Birkeland currents and the aurora.

Hydrogen is found in the neutral atomic state in the interstellar medium. Under ordinary conditions on Earth, elemental hydrogen exists as the diatomic gas, H 2.

However, hydrogen gas is very rare in the Earth's atmosphere 1 ppm by volume because of its light weight, which enables it to escape from Earth's gravity more easily than heavier gases. However, hydrogen is the third most abundant element on the Earth's surface, [80] mostly in the form of chemical compounds such as hydrocarbons and water. This charged 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 2 is produced in chemistry and biology laboratories, often as a by-product of other reactions; in industry for the hydrogenation of unsaturated substrates; and in nature as a means of expelling reducing equivalents in biochemical reactions.

This reaction is favored at low pressures but is nonetheless conducted at high pressures 2. This is because high-pressure H 2 is the most marketable product and pressure swing adsorption PSA purification systems work better at higher pressures. The product mixture is known as " synthesis gas 99 vip binary option signals because it is often used directly for the production of methanol and related compounds.

Hydrocarbons other than methane can be used to produce synthesis gas with varying product ratios. One of the many complications to this highly optimized technology is the formation of coke or carbon:. Consequently, steam reforming typically employs an excess of H 2 O.

Additional hydrogen can be recovered from the steam by use of carbon monoxide through the water gas shift reactionespecially with an iron oxide catalyst. This reaction is also a common industrial source of carbon dioxide: Other important methods for H 2 production include partial oxidation of hydrocarbons: Hydrogen is sometimes produced and consumed in the same industrial process, without being separated. In the Haber process for the production of ammoniahydrogen is generated from natural gas.

In the laboratoryH 2 is usually prepared by the reaction of dilute non-oxidizing acids on some reactive metals such as zinc with Kipp's apparatus.

H S01 E01 - L'Anniversaire

Aluminium can also produce H 2 upon treatment with bases:. The electrolysis of water is a simple method of producing hydrogen. A low voltage current is run through the water, and gaseous oxygen forms at the anode while gaseous hydrogen forms at the cathode.

Typically the cathode is made from platinum or another inert metal when producing hydrogen for storage. If, however, the gas is to be burnt on site, oxygen is desirable to assist the combustion, and so both electrodes would be made from inert metals.

Iron, for instance, would oxidize, and thus decrease the amount of oxygen given off. The theoretical maximum efficiency electricity used vs. An alloy of aluminium and gallium in pellet form added to water can be used to generate hydrogen. The process also produces aluminabut the expensive gallium, which prevents the formation of an oxide skin on the pellets, can be re-used.

This has important potential implications for a hydrogen economy, as hydrogen can be produced on-site and does not need to be transported. There are more than thermochemical cycles which can be used for water splittingaround a dozen of these cycles such as the iron oxide cyclecerium IV oxide—cerium III oxide cyclezinc zinc-oxide cyclesulfur-iodine cyclecopper-chlorine cycle and hybrid sulfur cycle are under research and in testing phase to produce hydrogen and oxygen from water and heat without using electricity.

Under anaerobic conditions, iron and steel algorithm for trading stocks are slowly oxidized by the protons of water concomitantly reduced in molecular hydrogen H 2.

The anaerobic corrosion of iron leads first to the formation of ferrous hydroxide green rust and can be described by the following reaction:. In its turn, how to get free gems and cash in campus life anaerobic conditions, the ferrous hydroxide Fe OH 2 can be oxidized by the protons of water to form magnetite and molecular hydrogen.

This process is described by the Schikorr reaction:. The well crystallized magnetite Fe 3 O 4 is thermodynamically more stable than the ferrous hydroxide Fe OH 2. This process occurs during the anaerobic corrosion of iron and steel in oxygen-free groundwater and in reducing soils below the water table. The corresponding reaction leading to the formation of magnetite Fe 3 O 4quartz Si Forex brokeri u srbiji 2 and hydrogen H 2 is the following:.

This reaction closely resembles the Schikorr reaction observed in the anaerobic oxidation of the ferrous hydroxide in contact with water. From all the fault gases formed in power transformershydrogen is the most common and is generated under most fault conditions; thus, formation of hydrogen is an early indication of serious problems in the transformer's life cycle. Large quantities of H 2 are needed in the petroleum and chemical industries.

The largest application of H 2 is for the processing "upgrading" of fossil fuels, and in the production of ammonia. The key consumers of H 2 in the petrochemical plant include hydrodealkylationhydrodesulfurizationand hydrocracking.

H 2 has several other important uses. H 2 is used as a hydrogenating agent, particularly in increasing the level of saturation of unsaturated fats and oils found in items such as margarineand in the production of methanol.

It is similarly the source of hydrogen in the manufacture of hydrochloric acid. H 2 is also used as a reducing agent of metallic ores. Hydrogen is highly soluble in many rare earth and transition metals [95] and is soluble in both nanocrystalline and amorphous metals. Apart from its use as a reactant, H 2 has wide applications in physics and engineering. It is used as a shielding gas in welding methods such as atomic hydrogen welding.

Liquid H 2 is used in cryogenic research, including superconductivity studies. In more recent applications, hydrogen is used pure or mixed with nitrogen sometimes called forming gas as a tracer gas for minute leak detection.

Applications can be found in the automotive, chemical, power generation, aerospace, and telecommunications industries. Hydrogen's rarer isotopes also each have specific applications. Deuterium hydrogen-2 is used in nuclear fission applications as a moderator to slow neutronsand in nuclear fusion reactions. The triple point temperature of equilibrium hydrogen is a defining fixed point on the ITS temperature scale at 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 densitylow viscosityand the highest specific heat and thermal conductivity of all gases. Hydrogen is not an energy resource, [] except in the hypothetical context of commercial nuclear fusion power plants using deuterium or tritiuma technology presently far from development.

Hydrogen may be obtained from fossil sources such as methanebut these sources are unsustainable. The energy density per unit volume of both liquid hydrogen and compressed hydrogen gas at any practicable pressure is significantly less than that of traditional fuel sources, although the energy density per unit fuel mass is higher. Hydrogen is employed to saturate broken "dangling" bonds of amorphous silicon and amorphous carbon that helps stabilizing material properties.

H 2 is a product of some types of anaerobic metabolism and is produced by several microorganismsusually via reactions catalyzed by iron - or nickel -containing enzymes called hydrogenases. These enzymes catalyze the reversible redox reaction between H 2 and its component two protons and two electrons. Creation of hydrogen gas occurs in the transfer of reducing equivalents produced during pyruvate fermentation to water.

H - definition of H by The Free Dictionary

Water splittingin which water is decomposed into its component protons, electrons, and oxygen, occurs in the light reactions in all photosynthetic organisms. Some such organisms, including the alga Chlamydomonas reinhardtii and cyanobacteriahave evolved a second step in the dark reactions in which protons and electrons are reduced to form H 2 gas by specialized hydrogenases in the chloroplast. Hydrogen poses a number of hazards to human safety, from potential detonations and fires when mixed with air to being an asphyxiant in its pure, oxygen -free form.

Moreover, hydrogen fire, while being extremely hot, is almost invisible, and thus can lead to accidental burns. Even interpreting the hydrogen data including safety data is confounded by a number of phenomena.

Hydrogen detonation parameters, such as critical detonation pressure and temperature, strongly depend on the container geometry. From Wikipedia, the free encyclopedia. This article is about the chemistry of hydrogen. For the physics of atomic hydrogen, see Hydrogen atom. For other uses, see Hydrogen disambiguation.

Spin isomers of hydrogen. Timeline of hydrogen technologies. Hydrogen economy and Hydrogen infrastructure. Biohydrogen and Biological hydrogen production Algae. CRC Handbook of Chemistry and Physics PDF 86th ed. CRC, Handbook of Chemistry and Physics. Chemical Rubber Company Publishing.

Van Nostrand's Encyclopedia of Chemistry. A Guide to the Elements. Retrieved 5 February Molecular Modeling in Chemical Engineering. Retrieved 4 May Professor Jim Al-Khalili 21 January Florida Solar Energy Center. Technical University of Denmark.

Retrieved 19 May University of Southern Maine. Retrieved 6 April A Comprehensive Guide to the Hazardous Properties of Chemical Substances. Handbook of Isotopes in the Cosmos: University of Nebraska Lincoln. Retrieved 20 May NASA Goddard Space Flight Center mirror. Retrieved 20 December NASA Goddard Space Flight Center. Retrieved 16 April Hydrogen Gas and Liquid Hydrogen".

Universal Industrial Gases, Inc. NASA Glenn Research Center Glenn Safety Manual, Document GRC-MQSA. Journal of Low Temperature Physics. National Renewable Energy Laboratory. Journal of the American Chemical Society. Retrieved 9 March Retrieved 4 March Retrieved 23 March Inorganic Chemistry 3rd ed. Journal of Physical Chemistry. Accounts of Chemical Research. Physics of Atomic Nuclei. Journal of Biomolecular NMR.

The New York Times. Retrieved 12 February International Atomic Energy Agency. Retrieved 8 March Experimental and Applied Acarology. Accessed on line 3 October Compendium of Chemical Terminology 2nd ed.

W Hughes; et al. Pure and Applied Chemistry. Research programmes in the Chemical Revolution". Method and appraisal in the physical sciences. The Critical Background to Modern Science, — Retrieved 22 October A chronological history of electrical development from B. Validation of international space station electrical performance model via on-orbit telemetry PDF. Retrieved 11 November Annual Review of Physical Chemistry. Archived from the original on Argonne National Laboratory, U. Department of Energy, Office of Science Laboratory.

University of California, San Diego. Universities of Illinois and Chicago. Department of Molecular and Optical Physics, University of Freiburg, Germany.

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Retrieved 25 November Annual Review of Energy and the Environment. Principles of Modern Chemistry 5th ed.

Retrieved 11 March The Samuel Roberts Noble Foundation. Archived from the original on 26 October Solar Thermochemical Hydrogen Generation Project. Retrieved 17 May Retrieved 13 July Los Alamos National Laboratory.

Materials Science and Engineering. Progress in Materials Science. Archived from the original on 16 July An unlikely but rewarding path". History of industrial gases. Hydrogen as Tracer Gas for Leak Detection. Retrieved 25 March Bulletin of the Atomic Scientists. Educational Foundation for Nuclear Science, Inc.

Retrieved 14 March Retrieved 16 March Hydrogen Program Press release. US Department of Energy. Archived from the original on 19 July International Journal of Hydrogen Energy. The Hype About Hydrogen: Fact And Fiction in the Race To Save The Climate 1st ed.

DOE Fuel Cell Technologies Program, FY Annual Progress Report. Hydrogen as a Fuel: Atmospheric Chemistry and Physics. The Journal of Biological Chemistry. United States Department of Energy. Retrieved 6 August Retrieved 24 March Retrieved 29 January McKetta; William Aaron Cunningham, eds.

Lactic acid to magnesium supply-demand relationships. Encyclopedia of Chemical Processing and Design. This audio file was created from a revision of the " Hydrogen " article datedand does not reflect subsequent edits to the article. Retrieved from " https: Hydrogen Chemical elements Diatomic nonmetals Biology and pharmacology of chemical elements Nuclear fusion fuels Airship technology Reducing agents Refrigerants Gaseous signaling molecules. Navigation menu Personal tools Not logged in Talk Contributions Create account Log in.

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