What is the origin of the symbol Hg for mercury?
Period 6 element
Mercury is a chemical element with the symbol Hg and atomic number 80. It is also known as quicksilver or hydrargyrum ( < Greek "" "water" and "" "silver"). A heavy, silvery d-block element, mercury is the only metal that is liquid at standard conditions for temperature and pressure; the only other element that is liquid under these conditions is bromine, though metals such as caesium, francium, gallium, and rubidium melt just above room temperature. With a freezing point of −38.83 °C and boiling point of 356.73 °C, mercury has one of the narrowest ranges of its liquid state of any metal.
Mg (magazine)
The magazine is named after the abbreviation for milligram, the metric used to measure the THC (psychoactive component) and CBD (non-psychoactive component) in cannabis products.
Barometer
Torricelli documented that the height of the mercury in a barometer changed slightly each day and concluded that this was due to the changing pressure in the atmosphere. He wrote: "We live submerged at the bottom of an ocean of elementary air, which is known by incontestable experiments to have weight". Inspired by Torricelli, Otto von Guericke on 5 December 1660 found that air pressure was unusually low and predicted a storm, which occurred the next day.
The mercury barometer's design gives rise to the expression of atmospheric pressure in inches or millimeters of mercury (mmHg). A torr was originally defined as 1 mmHg. The pressure is quoted as the level of the mercury's height in the vertical column. Typically, atmospheric pressure is measured between and of Hg. One atmosphere (1 atm) is equivalent to of mercury.
Design changes to make the instrument more sensitive, simpler to read, and easier to transport resulted in variations such as the basin, siphon, wheel, cistern, Fortin, multiple folded, stereometric, and balance barometers. Fitzroy barometers combine the standard mercury barometer with a thermometer, as well as a guide of how to interpret pressure changes. Fortin barometers use a variable displacement mercury cistern, usually constructed with a thumbscrew pressing on a leather diaphragm bottom (V in the diagram). This compensates for displacement of mercury in the column with varying pressure. To use a Fortin barometer, the level of mercury is set to zero by using the thumbscrew to make an ivory pointer (O in the diagram) just touch the surface of the mercury. The pressure is then read on the column by adjusting the vernier scale so that the mercury just touches the sightline at Z.. Some models also employ a valve for closing the cistern, enabling the mercury column to be forced to the top of the column for transport. This prevents water-hammer damage to the column in transit.
Hacettepe University Medical School
The emblem of the University was designed in 1967 by Dr. Yücel Tanyeri, then a second year medical student, in the likeness of a stag – the symbol of a Hittite deity discovered at the royal tombs in Alacahöyük. Inspired by this archeological symbol common to the region, the Stag was chosen as the symbol of the University, and was abstracted to represent a lowercase "h" – the first letter of the university's name.
Mercury(II) acetate
Mercury(II) acetate is the chemical compound with the formula Hg(OCCH). Commonly abbreviated Hg(OAc), this compound is employed as a reagent to generate organomercury compounds from unsaturated organic precursors.
Curium
Curium is a transuranic radioactive chemical element with symbol Cm and atomic number 96. This element of the actinide series was named after Marie and Pierre Curie – both were known for their research on radioactivity. Curium was first intentionally produced and identified in July 1944 by the group of Glenn T. Seaborg at the University of California, Berkeley. The discovery was kept secret and only released to the public in November 1947. Most curium is produced by bombarding uranium or plutonium with neutrons in nuclear reactors – one tonne of spent nuclear fuel contains about 20 grams of curium.
Hydrogen (disambiguation)
Hydrogen is a chemical element with symbol H and atomic number 1.
Period 5 element
Silver is a metallic chemical element with the chemical symbol Ag (, from the Indo-European root "*arg-" for "grey" or "shining") and atomic number 47. A soft, white, lustrous transition metal, it has the highest electrical conductivity of any element and the highest thermal conductivity of any metal. The metal occurs naturally in its pure, free form (native silver), as an alloy with gold and other metals, and in minerals such as argentite and chlorargyrite. Most silver is produced as a byproduct of copper, gold, lead, and zinc refining.
Millimeter of mercury
A millimetre of mercury is a manometric unit of pressure, formerly defined as the extra pressure generated by a column of mercury one millimetre high, and currently defined as exactly pascals. It is denoted by the symbol mmHg or mm Hg.
Taegeuk Chil Jang
The word "taegeuk" (, ) refers to the universe from which all things and values are derived. It is also the symbol that makes up the center of the flag of South Korea and the source for its name, "taegeukgi" (hangul: 태극기, where "gi" means "flag"). The taegeuk is commonly associated with Korean Taoism philosophical values as well as Korean shamanism.
Curie
The curie (symbol Ci) is a non-SI unit of radioactivity originally defined in 1910. According to a notice in "Nature" at the time, it was named in honour of Pierre Curie, but was considered at least by some to be in honour of Marie Curie as well.
Methylmercury
Methylmercury (sometimes methyl mercury) is an organometallic cation with the formula . It is the major source of organic mercury for all humans. It is a bioaccumulative environmental toxicant.
Mercury sulfide
When α-HgS is used as a red pigment, it is known as vermilion. The tendency of vermilion to darken has been ascribed to conversion from red α-HgS to black β-HgS. However β-HgS was not detected at excavations in Pompeii, where originally red walls darkened, and was attributed to the formation of Hg-Cl compounds (e.g., corderoite, calomel, and terlinguaite) and calcium sulfate, gypsum.
Ethylmercury
Ethylmercury (sometimes ethyl mercury) is a cation composed of an organic CHCH- species (an ethyl group) bound to a mercury(II) centre, making it a type of organometallic cation, and giving it a chemical formula is CHHg. It is one of the metabolites of thiomersal (thimerosal or sodium ethyl mercuric thiosalicylate), which is used as a preservative in some vaccines. The term "ethylmercury" is also sometimes used as a generic term to describe organomercury compounds which include the ethylmercury functional group, such as ethylmercury chloride and ethylmercury urea.
H I region
An HI region or H I region (read H one) is a cloud in the interstellar medium composed of neutral atomic hydrogen (HI), in addition to the local abundance of helium and other elements. (H is the chemical symbol for hydrogen, and "I" is the Roman numeral. It is customary in astronomy to use the Roman numeral I for neutral atoms, II for singly-ionised—HII is H in other sciences—III for doubly-ionised, e.g. OIII is O, etc.) These regions do not emit detectable visible light (except in spectral lines from elements other than hydrogen) but are observed by the 21-cm (1,420 MHz) region spectral line. This line has a very low transition probability, so requires large amounts of hydrogen gas for it to be seen. At ionization fronts, where HI regions collide with expanding ionized gas (such as an H II region), the latter glows brighter than it otherwise would. The degree of ionization in an HI region is very small at around 10 (i.e. one particle in 10,000). At typical interstellar pressures in galaxies like the Milky Way, HI regions are most stable at temperatures of either below 100 K or above several thousand K; gas between these temperatures heats or cools very quickly to reach one of the stable temperature regimes. Within one of these phases, the gas is usually considered isothermal, except near an expanding H II region. Near an expanding H II region is a dense HI region, separated from the undisturbed HI region by a shock front and from the H II region by an ionization front.
Mercury polycations
The best known polycation of mercury is , in which mercury has a formal oxidation state of +1. The ion was perhaps the first metal-metal bonded species confirmed. The presence of the ion in solution was shown by Ogg in 1898. In 1900, Baker showed the presence of HgCl dimers in the vapour phase. The presence of units in the solid state was first determined in 1926 using X-ray diffraction. The presence of the metal-metal bond in solution was confirmed using Raman spectroscopy in 1934.
Hugh Marshall
Prof Hugh Marshall FRS FRSE FCS (1868-1913) was a Scottish chemist who discovered persulphates in 1891. He was the inventor of Marshall's acid. In 1902 he proposed the modified sign of equality <=> which became standard in chemistry to represent dynamic equilibrium.
Jesus H. Christ
Using the name of Jesus Christ as an oath has been common for many centuries. But the precise origins of the letter "H" in the expression "Jesus H. Christ" are obscure. While many explanations have been proposed, the most widely accepted derivation is from the divine monogram of Christian symbolism. The symbol, derived from the first three letters of the Greek name of Jesus (), is transliterated iota-eta-sigma, which can look like IHS, (with lunate sigma), JHS or JHC ("J" was historically a mere variant of "I"; see J).
Phenyl(trichloromethyl)mercury
Also known is bis(trichloromethyl)mercury, Hg(CCl).
Verigy
Verigy was started by Hewlett Packard, reported to David Packard in the early days and spun off from Agilent Technologies in 2006. The company went public on the NASDAQ in June 2006. The CEO was Keith Barnes, who later became Chairman and CEO. The CFO was Bob Nikl. In 2011 Mr. Barnes moved to Chairman of the Board of Directors and Jorge Titinger became CEO and President. The company's NASDAQ symbol was VRGY.
Hg (equity firm)
In total, Hg has more than £9B / $13M assets under management. The company has close to 120 employees in two investment offices in London, UK and Munich, Germany, and serves over 100 institutional investors, including private and public pension funds, endowments, insurance companies and fund of funds.
Hg began life as Mercury Private Equity, the private equity arm of Mercury Asset Management plc, a long-established UK-based asset management firm. Mercury Asset Management was acquired by Merrill Lynch in 1997. In December 2000, the executives of Mercury Private Equity negotiated independence from Merrill Lynch, and HgCapital (as it was then known) was established as a fully independent partnership wholly owned by its Partners and employees, who together work with a common purpose and culture.
Scrubber
Mercury is a highly toxic element commonly found in coal and municipal waste. Wet scrubbers are only effective for removal of soluble mercury species, such as oxidized mercury, Hg. Mercury vapor in its elemental form, Hg, is insoluble in the scrubber slurry and not removed. Therefore, an additional process of Hg conversion is required to complete mercury capture. Usually halogens are added to the flue gas for this purpose. The type of coal burned as well as the presence of a selective catalytic reduction unit both affect the ratio of elemental to oxidized mercury in the flue gas and thus the degree to which the mercury is removed.
River Thames
Mercury (Hg) is an environmentally persistent heavy metal which at high concentrations can be toxic to marine life and humans. Sixty sediment cores of 1 m in depth, spanning the entire tidal River Thames, between Brentford and the Isle of Grain have been analysed for total Hg. The sediment records show a clear rise and fall of Hg pollution through history. Mercury concentrations in the River Thames decrease downstream from London to the outer Estuary with the total Hg levels ranging from 0.01 to 12.07 mg/kg, giving a mean of 2.10 mg/kg which is higher than many other UK and European river estuaries.
Metal toxicity
Mercury poisoning is a disease caused by exposure to mercury or its compounds. Mercury (chemical symbol Hg) is a heavy metal occurring in several forms, all of which can produce toxic effects in high enough doses. Its zero oxidation state Hg exists as vapor or as liquid metal, its mercurous state Hg exists as inorganic salts, and its mercuric state Hg may form either inorganic salts or organomercury compounds; the three groups vary in effects. Toxic effects include damage to the brain, kidney, and lungs. Mercury poisoning can result in several diseases, including acrodynia (pink disease), Hunter-Russell syndrome, and Minamata disease.
Fritz Johann Hansgirg
Fritz Johann Hansgirg (18911949) was an Austrian electrochemist and metallurgist who in 1928 invented the carbothermic magnesium reduction process (magnesium, like calcium, can be used to reduce uranium oxide to pure uranium metal for use in nuclear weapons), similar to the Pidgeon process. In 1934, he left Austria for the Empire of Japan where he worked with industrialist Shitagau Noguchi to set up a magnesium plant and further helped the Japanese build a pilot plant to produce heavy water by the Combined Electrolysis Catalytic Exchange (CECE) he invented. Coming to the United States in 1940, he worked with American industrialist Henry J. Kaiser to design a magnesium plant in California, but at the outbreak of World War II, Hansgirg was arrested by the FBI on a Presidential warrant and interned for "the duration of the war." After the war, the Soviet Union captured Hansgirg's plants in northern Korea, using the plants' processes and equipment for their atomic bomb project against the United States, likewise, using them in the Manhattan Project, the exact details of which still remain classified in both the United States and Russia.
Toxic heavy metal
The first emperor of unified China, Qin Shi Huang, it is reported, died of ingesting mercury pills that were intended to give him eternal life. The phrase "mad as a hatter" is likely a reference to mercury poisoning among milliners (so-called "mad hatter disease"), as mercury-based compounds were once used in the manufacture of felt hats in the 18th and 19th century. Historically, gold amalgam (an alloy with mercury) was widely used in gilding, leading to numerous casualties among the workers. It is estimated that during the construction of Saint Isaac's Cathedral alone, 60 workers died from the gilding of the main dome. Outbreaks of methylmercury poisoning occurred in several places in Japan during the 1950s due to industrial discharges of mercury into rivers and coastal waters. The best-known instances were in Minamata and Niigata. In Minamata alone, more than 600 people died due to what became known as Minamata disease. More than 21,000 people filed claims with the Japanese government, of which almost 3000 became certified as having the disease. In 22 documented cases, pregnant women who consumed contaminated fish showed mild or no symptoms but gave birth to infants with severe developmental disabilities. Since the industrial Revolution, mercury levels have tripled in many near-surface seawaters, especially around Iceland and Antarctica.
Diphenylmercury
Diphenylmercury is the organomercury compound with the formula Hg(CH). It is a white solid. The compound is of historic interest as a particularly stable organometallic compound but it finds few uses because of its high toxicity.
Mercury cadmium telluride
HgCdTe or mercury cadmium telluride (also cadmium mercury telluride, MCT, MerCad Telluride, MerCadTel, MerCaT or CMT) is an alloy of cadmium telluride (CdTe) and mercury telluride (HgTe) with a tunable bandgap spanning the shortwave infrared to the very long wave infrared regions. The amount of cadmium (Cd) in the alloy can be chosen so as to tune the optical absorption of the material to the desired infrared wavelength. 
CdTe is a semiconductor with a bandgap of approximately 1.5 electronvolts (eV) at room temperature. HgTe is a semimetal, which means that its bandgap energy is zero. Mixing these two substances allows one to obtain any bandgap between 0 and 1.5 eV.
Italian units of measurement
oncia = hg
Helium compounds
J. J. Manley claimed to have found gaseous mercury helide HeHg in 1925 HgHe; publishing the results in "Nature", but then had trouble finding a stable composition, and eventually gave up.
Dimethylmercury
Dimethylmercury ((CH)Hg) is an organomercury compound. A highly volatile, reactive, flammable, and colorless liquid, dimethylmercury is one of the strongest known neurotoxins, with a quantity of less than 0.1 mL capable of inducing severe mercury poisoning, and is easily absorbed through the skin. Dimethylmercury is capable of permeating many materials, including plastic and rubber compounds.
Mercury(I) sulfate
The crystal structure of mercurous sulfate is made up of Hg dumbbells and SO anions as main building units. Hg dumbbell is surrounded by four Oxygen atoms with Hg₋O distance ranging from 2.23 to 2.93 Å, whereas Hg-Hg distance is approximately 2.500Å.
Studies have shown mercury(I) sulfate to have the mercury atoms arranged in doublets with a bond distance of 2.500Å. The metal atom doublets are oriented parallel to the an axis in a unit cell. Mercury doublets form part of infinite chain SO - Hg - Hg - SO - Hg - Hg - … The Hg - Hg - O bond angle is 165°±1 . The chain crosses the unit cell diagonally. The mercury sulfate structure is held together by weak Hg-O interactions. The SO does not act as a single anion, but rather coordinated to the mercury metal.
Gdańsk University of Technology
Daniel Gabriel Fahrenheit (1686-1736) was born in Gdańsk. He is mainly known for being the first to use mercury in temperature measuring devices (previously alcohol was used) and developed his own scale of 0 to 212 degrees.
Relativistic quantum chemistry
Au(g) and Hg(g) are analogous, at the least in having the same nature of difference, to H(g) and He(g). It is for the relativistic contraction of the 6s orbital that gaseous mercury can be called a pseudo noble gas.
Hal Huggins
In 1996, a Colorado state judge recommended that Huggins's dental license be revoked, citing his use of "'deceptive yet seductive advertising' to trick chronically ill patients into thinking that the true cause of their illness was mercury." Huggins's license was subsequently revoked by the Colorado State Board of Dental Examiners for gross negligence and the use of unnecessary and unproven procedures. "TIME" reported the judge's conclusion that Huggins "diagnosed 'mercury toxicity' in all his patients, including some without amalgam fillings."
Symbol (chemistry)
Earlier chemical element symbols stem from classical Latin and Greek vocabulary. For some elements, this is because the material was known in ancient times, while for others, the name is a more recent invention. For example, "He" is the symbol for helium (New Latin name, not known in ancient Roman times), "Pb" for lead ("plumbum" in Latin), and "Hg" for mercury ("hydrargyrum" in Greek). Some symbols come from other sources, like "W" for tungsten ("Wolfram" in German, not known in Roman times).
Karen Wetterhahn
Dimethylmercury was a compound used, almost exclusively, as a reference standard for Hg nuclear magnetic resonance (NMR) measurements, a particular type of specialized chemical analysis.
Karen Wetterhahn
At the time, dimethylmercury was the common calibration standard for Hg NMR spectroscopy because it has certain advantages over the alternatives that exist. As a consequence of Wetterhahn's accident, safety recommendations have been revised, and the use of dimethylmercury for any purpose has been highly discouraged.
Isotopes of mercury
Hg, producible from Tl, was found in 2010 to be capable of an unusual form of spontaneous fission. The fission products are Kr and Ru.
Mercury selenide
Along with other II-VI compounds, colloidal nanocrystals of HgSe can be formed.HgSe is non-toxic as long as it is not ingested due to its insolubility. Toxic hydrogen selenide fumes can be evolved on exposure to acids. HgSe is a relatively stable compound which might mean that it is less toxic than elemental mercury or many organometallic mercury compounds. Selenium's ability to complex with mercury has been proposed as a reason for the lack of mercury toxicity in deep sea fish despite high mercury levels.
Oganesson
Oganesson is a synthetic chemical element with symbol Og and atomic number 118. It was first synthesized in 2002 at the Joint Institute for Nuclear Research (JINR) in Dubna, near Moscow in Russia, by a joint team of Russian and American scientists. In December 2015, it was recognized as one of four new elements by the Joint Working Party of the international scientific bodies IUPAC and IUPAP. It was formally named on 28 November 2016. The name is in line with the tradition of honoring a scientist, in this case the nuclear physicist Yuri Oganessian, who has played a leading role in the discovery of the heaviest elements in the periodic table. It is one of only two elements named after a person who was alive at the time of naming, the other being seaborgium; it is also the only element whose namesake is alive today.
Eta
In chemistry, the letter H as symbol of enthalpy sometimes is said to be a Greek eta, but since enthalpy comes from ἐνθάλπος, which begins in a smooth breathing and epsilon, it is more likely a Latin H for 'heat'.
Mercury polycations
Compounds containing the linear (mercury()) and (mercury()) cations have been synthesised. These ions are only known in the solid state in compounds such as and . The Hg–Hg bond length is 255 pm in , and 255–262 pm in . The bonding involves 2-centre-2-electron bonds formed by 6s orbitals.
Argimusco
The Virgin is the center of the “Mirror of the stars” staged at Argimusco, since all other figures play an ancillary role with respect to it. As a matter of fact, the sun rises in Virgo at summer solstice of 10,500 BC. It embodies the feminine divine figure, which is lunar liquid mercury, as opposed to the divine Apollonian, masculine, solar disk, put in alchemical terms. As a mercurial element, it is precisely located near the Serpens constellation and the bearer of snakes (Ophiuchus), or the symbol of the Caduceus of Hermes (Mercury) consisting of a rod around which wraps themselves, in fact, two snakes (now the symbol of medicine). Particularly significant, high on the megalith of the Virgo is a rectangular pool, that we suppose was used for ritual ablutions.
New Idria Mercury Mine
Mercury, known to be highly toxic, has been found in various forms in Idria: elemental mercury (Hg(0)), inorganic mercury (Hg(II)) and monomethyl mercury(CH3Hg+, also called MMHg). MMHg, a potent neurotoxin, poses the greatest threat to organisms. Measurements were taken by collecting water samples, which were later analyzed by tin chloride reduction, atomic fluorescence, and cold vapor atomic fluorescence spectrometry. The samples showed that mercury discharge and interaction was occurring throughout the course of the San Carlos Creek. The biggest contributions were found in the acid mine drainage and the mine tailings 1.2 km downstream from the drainage input.
Henry D. Hubbard
Henry D. Hubbard was a member of the U.S. Bureau of Standards in the 1920s. He modernized Mendeleev's periodic table and in 1924 he produced a Periodic Table of Elements (called the Periodic Chart of the Atoms) which was distributed to schools and universities. This version of the periodic table placed the main groups in columns with some later groups taking up two rows per period and the Group VIIIB transition metals displayed out to the right of the noble gases. The noble gases themselves were shown first in Column 1 (Valence 0) and repeated in Column 9 (Group VIII). The table is also notable for including the solo Neutron as an entry on its own, "above" Hydrogen, and given the symbol lower-case 'n'.
Red mercury
When red mercury first appeared on the international black market 15 years ago, the supposedly top secret nuclear material was 'red' because it came from Russia. When it resurfaced last year in the formerly communist states of Eastern Europe it had unaccountably acquired a red colour. But then, as a report from the US Department of Energy reveals, mysterious transformations are red mercury's stock in trade.
Mercury (element)
In the European Union, the directive on the Restriction of the Use of Certain Hazardous Substances in Electrical and Electronic Equipment (see RoHS) bans mercury from certain electrical and electronic products, and limits the amount of mercury in other products to less than 1000 ppm. There are restrictions for mercury concentration in packaging (the limit is 100 ppm for sum of mercury, lead, hexavalent chromium and cadmium) and batteries (the limit is 5 ppm). In July 2007, the European Union also banned mercury in non-electrical measuring devices, such as thermometers and barometers. The ban applies to new devices only, and contains exemptions for the health care sector and a two-year grace period for manufacturers of barometers.
Norway enacted a total ban on the use of mercury in the manufacturing and import/export of mercury products, effective 1 January 2008. In 2002, several lakes in Norway were found to have a poor state of mercury pollution, with an excess of 1 µg/g of mercury in their sediment.
In 2008, Norway's Minister of Environment Development Erik Solheim said: "Mercury is among the most dangerous environmental toxins. Satisfactory alternatives to Hg in products are
available, and it is therefore fitting to induce a ban."
Erg
In 1864, Rudolf Clausius proposed the Greek word ("") "ergon" for the unit of energy, work and heat. In 1873, a committee of the British Association for the Advancement of Science, including British physicists James Clerk Maxwell and William Thomson recommended the general adoption of the centimetre, the gramme, and the second as fundamental units (C.G.S. System of Units). To distinguish derived units, they recommended using the prefix ""C.G.S. unit of ..."" and requested that the word "erg" or "ergon" be strictly limited to refer to the "C.G.S. unit of energy".
Mercury polycations
The golden yellow compound ), named "alchemists' gold" by its discoverers, contains perpendicular chains of Hg atoms.
Mercury(II) hydroxide
Mercury(II) hydroxide or mercury dihydroxide is an inorganic metal hydroxide with the chemical formula HgHO or more commonly written as Hg(OH).
Mercury(I) bromide
In common with other Hg(I) (mercurous) compounds which contain linear X-Hg-Hg-X units, HgBr contains linear BrHgBr units with an Hg-Hg bond length of 249 pm (Hg-Hg in the metal is 300 pm) and an Hg-Br bond length of 271 pm. The overall coordination of each Hg atom is octahedral as, in addition to the two nearest neighbours, there are four other Br atoms at 332 pm. The compound is often formulated as Hg 2Br, although it is actually a molecular compound.
Chalcogen
Oxygen's name comes from the Greek words "oxy genes", meaning "acid-forming". Sulfur's name comes from either the Latin word "sulfurium" or the Sanskrit word "sulvere"; both of those terms are ancient words for sulfur. Selenium is named after the Greek goddess of the moon, Selene, to match the previously-discovered element tellurium, whose name comes from the Latin word "telus", meaning earth. Polonium is named after Marie Curie's country of birth, Poland. Livermorium is named for the Lawrence Livermore National Laboratory.
Heusler compound
The term derives from the name of German mining engineer and chemist Friedrich Heusler, who studied such a compound in 1903. It contained two parts copper, one part manganese, and one part tin, that is CuMnSn, and has the following properties. Its magnetism varies considerably with heat treatment and composition. It has a room-temperature saturation induction of around 8,000 gauss, which exceeds that of the element nickel (around 6100 gauss) but is smaller than that of iron (around 21500 gauss). For early studies see. In 1934, Bradley and Rogers showed that the room-temperature ferromagnetic phase was a fully ordered structure of the L2 type. This has a primitive cubic lattice of copper atoms with alternate cells body-centered by manganese and aluminium. The lattice parameter is 5.95 Å. The molten alloy has a solidus temperature of about 910 °C. As it is cooled below this temperature, it transforms into disordered, solid, body-centered cubic beta-phase. Below 750 °C, a B2 ordered lattice forms with a primitive cubic copper lattice, which is body-centered by a disordered manganese-aluminium sublattice. Cooling below 610 °C causes further ordering of the manganese and aluminium sub-lattice to the L2 form. In non-stoichiometric alloys, the temperatures of ordering decrease, and the range of anealing temperatures, where the alloy does not form microprecipitates, becomes smaller than for the stoichiometric material.
Cinnabar
Cinnabar () and cinnabarite (), likely deriving from the ("kinnabari"), refer to the common bright scarlet to brick-red form of mercury(II) sulfide (HgS) that is the most common source ore for refining elemental mercury, and is the historic source for the brilliant red or scarlet pigment termed vermilion and associated red mercury pigments.
Inch of mercury
In air conditioning and refrigeration, inHg is often used to describe "inches of mercury vacuum", or pressures below ambient atmospheric pressure, for recovery of refrigerants from air conditioning and refrigeration systems, as well as for leak testing of systems while under a vacuum, and for dehydration of refrigeration systems. The low-side gauge in a refrigeration gauge manifold indicates pressures below ambient in "inches of mercury vacuum" (inHg), down to a 30 inHg vacuum.
Mercury transporter
The MerF protein encoded on plasmid pMER327/419 is an 81 residue polypeptide with two putative TMSs. It catalyzes uptake of Hg in preparation for reduction by mercuric reductase. The MerF gene is found on mercury resistant plasmids from many gram-negative bacteria, but the sequence of the protein from these plasmids is the same. Limited sequence similarity is shown with the first two TMSs of MerT (TC# 1.A.72.3) and MerC (TC# 1.A.72.4). MerF has two vicinal pairs of cysteine residues which are involved in the transport of Hg(II) across the membrane and are exposed to the cytoplasm. Some members of the MerF family have been designated MerH.
Jan Aaseth
The essential trace element selenium (Se) appears to be an antidote to mercury (Hg). Se-containing molecules are targets for Hg binding that may at least partially mediate the biological outcome of Hg-Se interaction. Molecular interaction between these elements also involves mutual interaction between Hg and various selenoproteins. Experimental data demonstrate that Se treatment modifies brain Hg retention, modulates neurotoxicity and oxidative stress in the nervous tissue of animals. Human data also indicate that molecular interaction between Hg and Se may have a significant influence on neurodevelopment and neurodegeneration. The hypothesized effectiveness of Se protection against Hg neurotoxicity may be determined by the dose of elements as well as by their particular chemical forms.
Mercury poisoning
All of these, except elemental liquid mercury produce toxicity or death with less than a gram. Mercury's zero oxidation state (Hg) exists as vapor or as liquid metal, its mercurous state (Hg) exists as inorganic salts, and its mercuric state (Hg) may form either inorganic salts or organomercury compounds.
Mercury nitride
Mercury nitride describes chemical compounds that contain mercury cations and nitrido anions. Binary mercury nitrides, e.g. stoichiometrically compounds such as HgN, are not well characterized and are probably unstable in the condensed phase under ordinary conditions. A nitride of mercury has been reported in the form of [HgN](NO). This reddish solid adopts a network structure consisting of NHg tetrahedra linked by nitrate ligands.
Roentgenium
Roentgenium is a chemical element with symbol Rg and atomic number 111. It is an extremely radioactive synthetic element that can be created in a laboratory but is not found in nature. The most stable known isotope, roentgenium-282, has a half-life of 100 seconds, although the unconfirmed roentgenium-286 may have a longer half-life of about 10.7 minutes. Roentgenium was first created in 1994 by the GSI Helmholtz Centre for Heavy Ion Research near Darmstadt, Germany. It is named after the physicist Wilhelm Röntgen (also spelled Roentgen), who discovered X-rays.
Mercury polycations
Mercury polycations are polyatomic cations that contain only mercury atoms. The best known example is the ion, found in mercury(I) (mercurous) compounds. The existence of the metal-metal bond in Hg(I) compounds was established using X-ray studies in 1927 and Raman spectroscopy in 1934 making it one of the earliest, if not the first, covalent metal-metal bonds to be characterised.
Mercury(I) fluoride
In common with other Hg(I) (mercurous) compounds which contain linear X-Hg-Hg-X units, HgF contains linear FHgF units with an Hg-Hg bond length of 251 pm (Hg-Hg in the metal is 300 pm) and an Hg-F bond length of 214 pm. The overall coordination of each Hg atom is a distorted octahedron; in addition to the bonded F and other Hg of the molecule, there are four other F atoms at 272 pm. The compound is often formulated as Hg 2F.
Geir Bjørklund
One heavy metal that has been linked to autism is mercury (Hg).
Hertz
The hertz (symbol: Hz) is the derived unit of frequency in the International System of Units (SI) and is defined as one cycle per second. It is named for Heinrich Rudolf Hertz, the first person to provide conclusive proof of the existence of electromagnetic waves. Hertz are commonly expressed in multiples: kilohertz (10 Hz, kHz), megahertz (10 Hz, MHz), gigahertz (10 Hz, GHz), terahertz (10 Hz, THz), petahertz (10 Hz, PHz), and exahertz (10 Hz, EHz).
Fritz Johann Hansgirg
Mrs. Hansgirg's letter on behalf of husband was forwarded by First Lady Eleanor Roosevelt to Federal Bureau of Investigation (FBI) Director J. Edgar Hoover, who in turn consulted with the Director of the Alien Enemy Control Unit resulting in Hansgirg being paroled to the President of Black Mountain College, in North Carolina.The decision was taken on the advice of the famous Austrian scientist Karl Terzaghi. In college Hansgirg began to combine the teaching of chemistry and physics with research and business activities. Black Mountain College had a reputation of Art School, but under the leadership of Hansgirg were found on campus deposits mica and began their commercial use. In 1943, he had applied for a new modified method of producing magnesium The feedstock in this process are mineral rocks rich in olivine, a reducing agent - calcium carbide. The deposits of olivine were in North Carolina. In addition to magnesium, there are also obtained the cement and iron alloys. Hansgirg remade with the involvement of students old college bath in laboratory and built there pilot plant producing magnesium. He also created Corporation of North Carolina Magnesium Development Corporation, and gave 20% of the shares to the college. This project has not successful pilot installation producing magnesium burned in 1948, and a year earlier Hansgirg moved to New York.
In 23 July 1949, Hansgirg died "unexpectedly" at the age of 58 with the cause of death unknown, but suspected to be due his decades ingestion of magnesium resulting in Hypermagnesemia.
Hryvnia sign
The hryvnia sign is a cursive Ukrainian Cyrilic letter He ("г"), or a mirrored letter S, with a double horizontal stroke, symbolising stability, similar to that used in other currency symbols such as ¥ or €. Hryvnia is abbreviated "грн" (hrn) in Ukrainian. The hryvnia sign ₴ was released in March 2004. The specific design of the hryvnia sign was a result of a public contest held by National Bank of Ukraine in 2003. The bank announced that it would not take any special steps of promoting the sign, but expressed expectations that the recognition and the technical possibilities of rendering the sign would follow. As soon as the sign was announced, a proposal to encode it was written. The sign was Unicode encoded as in version 4.1, as published in 2005.
The symbol appears in the filigree of the 1 Hryvnia banknote.
Seaborgium
The name "seaborgium" and symbol "Sg" were announced at the 207th national meeting of the American Chemical Society in March 1994 by Kenneth Hulet, one of the co-discovers. However, IUPAC resolved in August 1994 that an element could not be named after a living person, and Seaborg was still alive at the time. Thus, in September 1994, IUPAC recommended a set of names in which the names proposed by the three laboratories (the third being the GSI Helmholtz Centre for Heavy Ion Research in Darmstadt, Germany) with competing claims to the discovery for elements 104 to 109 were shifted to various other elements, in which "rutherfordium" (Rf), the Berkeley proposal for element 104, was shifted to element 106, with "seaborgium" being dropped entirely as a name.
Hg
Hg, hg or HG may also refer to:
Mercury(II) oxide
HgO is sometimes used in the production of mercury as it decomposes quite easily. When it decomposes, oxygen gas is generated.
Mercury transporter
Hg or methyl-Hg (out) → Hg or methyl-Hg (in)
Mercury(I) chloride
The Hg–Hg bond length of 253 pm (Hg–Hg in the metal is 300 pm) and the Hg–Cl bond length in the linear HgCl unit is 243 pm. The overall coordination of each Hg atom is octahedral as, in addition to the two nearest neighbours, there are four other Cl atoms at 321 pm. Longer mercury polycations exist.
Hazard symbol
The international radiation symbol (also known as the trefoil) first appeared in 1946, at the University of California, Berkeley Radiation Laboratory. At the time, it was rendered as magenta, and was set on a blue background. The original version used in America is magenta against a yellow background, and it is drawn with a central circle of radius "R", an internal radius of 1.5"R" and an external radius of 5"R" for the blades, which are separated from each other by 60°. The trefoil is black in the international version, which is also used in America.
Mersalyl
Mersalyl (Mersal) is an organomercury compound (mercurial diuretic). It is only rarely used as a drug, having been superseded by diuretic medications that do not contain mercury and are therefore less toxic. It features a Hg(II) centre. Mersalyl was originally adapted from calomel (HgCl), a diuretic discovered by Paracelsus.
Gold
Only the mercury isotope Hg, which occurs with a frequency of 0.15% in natural mercury, can be converted to gold by neutron capture, and following electron capture-decay into Au with slow neutrons. Other mercury isotopes are converted when irradiated with slow neutrons into one another, or formed mercury isotopes which beta decay into thallium.
Azoth
Azoth was considered to be a universal medication or universal solvent, and was sought for in alchemy. Similar to another alchemical idealized substance, alkahest, azoth was the aim, goal and vision of many alchemical works. Its symbol was the Caduceus. The term, while originally a term for an occult formula sought by alchemists much like the philosopher's stone, became a poetic word for the element mercury. The name is Medieval Latin, an alteration of "azoc", being originally derived from the Arabic "al-zā'būq", "the mercury".
Mercury(I) chloride
Mercurous chloride decomposes into mercury(II) chloride and elemental mercury upon exposure to UV light.
The formation of Hg can be used to calculate the number of photons in the light beam, by the technique of actinometry.
Mercury(I) nitrate
Mercury(I) nitrate is a chemical compound with the formula Hg(NO). It is used in the preparation of other mercury(I) compounds, and is toxic.
Erg
The erg is a unit of energy and work equal to 10 joules. It originated in the centimetre–gram–second (CGS) system of units. It has the symbol "erg". The erg is not an SI unit. Its name is derived from "ergon" (ἔργον), a Greek word meaning "work" or "task".
El Hierro
The name "El Hierro", although spelled like the Spanish word for 'iron', is not related to that word. The "H" in the name of the metal is derived from the "F" of Latin "ferrum" (compare "higa" for 'fig'). The "H" in the name of the island dates back to the time in Old Spanish orthography when the distinction between the letters "I" and "J" was not yet established and a silent "h" was written before word-initial "ie" to ensure that the "i" was read as a semivowel, not as the consonant .
Gravitational metric system
The hyl, metric slug (mug), or TME (German: technische Masseneinheit, technical mass unit), is the mass that accelerates at 1 m/s under a force of 1 kgf. The hyl has also been used as the unit of mass in a metre–gram-force–second (mgfs) system.
CB military symbol
Military symbols evolved out of the First World War from the British in part for secrecy, and to simplify reference to chemicals by something other than a chemical name. These symbols were sometimes applied as marking on weapons to indicate the agent contents. Military symbols constantly changed and had transitory definitions. For example, mustard gas was assigned the military symbol originally HS for "Hun Stuff". Later in the First World War the S in HS signified mustard gas that had about 25% solvent added to it. This was only in England, as HS was adopted as the military symbol by the United States – signifying crude mustard. In the Second World War the purity of mustard gas was improved through distillation, and this purified chemical warfare agent was designated HD. When it was mixed with a thickener (Agent VV), it was given the symbol HV. Today mustard gas is indicated by the single capital letter H, but HD is still in common use.
Merchant's mark
One such symbol combined the mystical "Sign of Four" with the merchant's name or initials. The "Sign of Four" was an outgrowth of an ancient symbol adopted by the Romans and by Christianity, Chi Rho (XP), standing for the first two letters of Christus in Greek letters; this was simplified to a reversed "4" in Medieval times. The evolution of this symbol is shown in M. J. Shah's article. The "Sign of Four" is called the "Staff of Mercury" (Caduceus) in German and Scandinavian literature on house marks.
Heinrich Hertz
The SI unit "hertz" (Hz) was established in his honor by the International Electrotechnical Commission in 1930 for frequency, an expression of the number of times that a repeated event occurs per second. It was adopted by the CGPM (Conférence générale des poids et mesures) in 1960, officially replacing the previous name, "cycles per second" (cps).
Mercury telluride
Mercury telluride (HgTe) is a binary chemical compound of mercury and tellurium. It is a semi-metal related to the II-VI group of semiconductor materials. Alternative names are mercuric telluride and mercury(II) telluride.
Organomercury
A general synthetic route to organomercury compounds entails alkylation with Grignard reagents and organolithium compounds. Diethylmercury results from the reaction of mercury chloride with two equivalents of ethylmagnesium bromide, a conversion that would typically be conducted in diethyl ether solution. The resulting (CHCH)Hg is a dense liquid (2.466 g/cm) that boils at 57 °C at 16 torr. The compound is slightly soluble in ethanol and soluble in ether.
Seaborgium
Seaborgium is a synthetic chemical element with symbol Sg and atomic number 106. It is named after the American nuclear chemist Glenn T. Seaborg. As a synthetic element, it can be created in a laboratory but is not found in nature. It is also radioactive; the most stable known isotope, Sg, has a half-life of approximately 14 minutes.
AR Aurigae
The primary component of AR Aurigae is known to be a mercury-manganese star, also known as an HgMn star. As the name implies, these stars have over-abundances of the elements mercury and manganese, and also often xenon and other elements. Because AR Aurigae is an eclipsing binary (in fact, it is the only known eclipsing binary with a mercury-manganese star), accurate characterization of its parameters has been made possible. Based on the light-time effect observed from the stars, it is inferred that there is a third star with a mass of , orbiting at a separation of 13 au every 23.7 years.
Hg
Hg is the chemical symbol of Mercury.
Chalcogen
In the 19th century, Jons Jacob Berzelius suggested calling the elements in group 16 "amphigens", as the elements in the group formed amphid salts (salts of oxyacids) The term received some use in the early 1800s but is now obsolete. The name "chalcogen" comes from the Greek words "χαλκος" (chalkos, literally "copper"), and "γενές" (genes, born, gender, kindle). It was first used in 1932 by Wilhelm Biltz's group at the University of Hanover, where it was proposed by Werner Fischer. The word "chalcogen" gained popularity in Germany during the 1930s because the term was analogous to "halogen". Although the literal meanings of the Greek words imply that "chalcogen" means "copper-former", this is misleading because the chalcogens have nothing to do with copper in particular. "Ore-former" has been suggested as a better translation, as the vast majority of metal ores are chalcogenides and the word "χαλκος" in ancient Greek was associated with metals and metal-bearing rock in general; copper, and its alloy bronze, was one of the first metals to be used by humans.
Trivial name
Nine elements were known by the Middle Ages – gold, silver, tin, mercury, copper, lead, iron, sulfur, and carbon. Mercury was named after the planet, but its symbol was derived from the Latin "hydrargyrum", which itself comes from the greek "υδράργυρος", meaning liquid silver; mercury is also known as quicksilver in English. The symbols for the other eight are also derived from descriptions of their properties in Latin.
Silver
Silver is a chemical element with symbol Ag (from the Latin "", derived from the Proto-Indo-European "h₂erǵ": "shiny" or "white") and atomic number 47. A soft, white, lustrous transition metal, it exhibits the highest electrical conductivity, thermal conductivity, and reflectivity of any metal. The metal is found in the Earth's crust in the pure, free elemental form ("native silver"), as an alloy with gold and other metals, and in minerals such as argentite and chlorargyrite. Most silver is produced as a byproduct of copper, gold, lead, and zinc refining.
Mercury(I) sulfate
Mercury(I) sulfate, commonly called mercurous sulphate (UK) or mercurous sulfate (US) is the chemical compound HgSO. Mercury(I) sulfate is a metallic compound that is white, pale yellow or beige powder. It is a metallic salt of sulfuric acid formed by replacing both hydrogen atoms with mercury(I). It is highly toxic; it could be fatal if inhaled, ingested, or absorbed by skin.
Inch of mercury
Inch of mercury (inHg and ″Hg) is a unit of measurement for pressure. It is still used for barometric pressure in weather reports, refrigeration and aviation in the United States.
Mercury selenide
Mercury selenide (HgSe) is a chemical compound of mercury and selenium. It is a grey-black crystalline solid semi-metal with a sphalerite structure. The lattice constant is 0.608 nm.
Liquid metal
A few elemental metals are liquid at or near room temperature. The most well known is mercury(Hg), which is molten above −38.8 °C (234.3 K, −37.9 °F). Others include caesium(Cs), which has a melting point of 28.5 °C (83.3 °F), rubidium (Rb)(39 °C [102 °F]), francium (Fr)(estimated at 27 °C [81 °F]), and gallium (Ga)(30 °C [86 °F]).
Methylmercury
"Methylmercury" is a shorthand for "methylmercury cation", and is more correctly ""methylmercury(1+) cation"" or ""methylmercury(II) cation"". It is composed of a methyl group (-) bonded to a mercury ion; its chemical formula is (sometimes written as MeHg).
Archer Maclean's Mercury
Archer Maclean's Mercury is a video game for the PlayStation Portable, first released in April 2005 in North America. In Japan, the game was released under the name [Hg] Hydrium. "Mercury" is a puzzle game developed by the eponymous British game programmer, Archer MacLean. In "Mercury", the player tilts a level in order to get a drop of mercury to its appointed destination, in a similar fashion to "Marble Madness". Differences include newer obstacles and the ability for the mercury to morph, split and transform around the levels. The game was originally designed to use a tilt sensor that plugged into the PSP's USB port, but this was never released.
Mercury transporter
The MerC protein encoded on the IncJ plasmid pMERPH of the "Shewanella putrefaciens" mercuric resistance operon is 137 amino acids in length and possesses four putative transmembrane α-helical spanners (TMSs). It has been shown to bind and take up Hg ions. "merC" genes are encoded on several plasmids of gram-negative bacteria and may also be chromosomally encoded. MerC proteins are homologous to other bacterial Hg bacterial transporters.
Procter &amp; Gamble
P&G's former logo originated in 1851 as a crude cross that barge workers on the Ohio River painted on cases of P&G star candles to identify them. P&G later changed this symbol into a trademark that showed a man in the moon overlooking 13 stars, said to commemorate the original 13 colonies.
Period 5 element
Cadmium is a chemical element with the symbol Cd and atomic number 48. This soft, bluish-white metal is chemically similar to the two other stable metals in group 12, zinc and mercury. Like zinc, it prefers oxidation state +2 in most of its compounds and like mercury it shows a low melting point compared to transition metals. Cadmium and its congeners are not always considered transition metals, in that they do not have partly filled d or f electron shells in the elemental or common oxidation states. The average concentration of cadmium in the Earth's crust is between 0.1 and 0.5 parts per million (ppm). It was discovered in 1817 simultaneously by Stromeyer and Hermann, both in Germany, as an impurity in zinc carbonate.