"standard incandescent light socket supplied with the proper voltage. A very closely related lamp design called the metal halide lamp uses various compounds in an amalgam with the mercury. Sodium iodide and scandium iodide are commonly in use. These lamps can produce much better quality light without resorting to phosphors. If they use a starting electrode, there is always a thermal shorting switch to eliminate any electrical potential between the main electrode and the starting electrode once the lamp is lit. (This electrical potential in the presence of the halides can cause the failure of the glass/metal seal). More modern"
"Mercury(I) sulfide Mercury(I) sulfide or mercurous sulfide is a hypothetical chemical compound of mercury and sulfur, with elemental formula . Its existence has been disputed; it may be stable below 0 °C or in suitable environments, but is unstable at room temperature, decomposing into metallic mercury and mercury(II) sulfide (mercuric sulfide, cinnabar). This compound was described in the 19th century by Berzelius as a black precipitate obtained by passing hydrogen sulfide through solutions of mercury(I) salts. As of 1825, the London Pharmacopoeia listed a compound called ""Ethiops-mineral"" or ""Hydrargyri Sulphuretum Nigrum"" (""black sulfide of mercury""), a black powder that was"
"Mercury sulfide Mercury sulfide, mercuric sulfide, mercury sulphide, or mercury(II) sulfide is a chemical compound composed of the chemical elements mercury and sulfur. It is represented by the chemical formula HgS. It is virtually insoluble in water. HgS is dimorphic with two crystal forms: Crystals of red, α-HgS, are optically active. This is caused by the Hg-S helices in the structure. β-HgS is precipitated as a black powder when HS is bubbled through solutions of Hg(II) salts. β-HgS is unreactive to all but concentrated acids. Mercury metal is produced from the cinnabar ore by roasting in air and condensing the"
"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. ""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). As a positively charged ion it readily combines with anions such as chloride (), hydroxide () and nitrate (). It also has very high affinity for sulfur-containing anions, particularly the thiol (-) groups"
"Mercury (element) Mercury is a chemical element with symbol Hg and atomic number 80. It is commonly known as quicksilver and was formerly named hydrargyrum ( ). A heavy, silvery d-block element, mercury is the only metallic element 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, gallium, and rubidium melt just above room temperature. Mercury occurs in deposits throughout the world mostly as cinnabar (mercuric sulfide). The red pigment vermilion is obtained by grinding natural cinnabar or synthetic mercuric sulfide. Mercury"
"precludes there being much common chemistry between mercury and gold, though there are similarities between mercury(I) and gold(I) such as the formation of linear dicyano complexes, [M(CN)]. According to IUPAC's definition of transition metal as ""an element whose atom has an incomplete d sub-shell, or which can give rise to cations with an incomplete d sub-shell"", zinc and cadmium are not transition metals, while mercury is. This is because only mercury is known to have a compound where its oxidation state is higher than +2, in mercury(IV) fluoride (though its existence is disputed, as later experiments trying to confirm its"
"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. Given the comparable electronegativities of mercury and carbon, the mercury-carbon bond is"
"over metallic mercury in a closed bottle for over 5 years developed a crust over the metal that was found to be mercurous sulfide. Mercury(I) sulfide Mercury(I) sulfide or mercurous sulfide is a hypothetical chemical compound of mercury and sulfur, with elemental formula . Its existence has been disputed; it may be stable below 0 °C or in suitable environments, but is unstable at room temperature, decomposing into metallic mercury and mercury(II) sulfide (mercuric sulfide, cinnabar). This compound was described in the 19th century by Berzelius as a black precipitate obtained by passing hydrogen sulfide through solutions of mercury(I) salts."
"layers of mercury atoms separated by layers of anions. They are both superconductors below 7 K. 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. Other mercury polycations are the linear and ions, and the triangular ion and a number of chain and layer polycations. The best known"
"Amalgam (chemistry) An amalgam is an alloy of mercury with another metal, which may be a liquid, a soft paste or a solid, depending upon the proportion of mercury. These alloys are formed through metallic bonding, with the electrostatic attractive force of the conduction electrons working to bind all the positively charged metal ions together into a crystal lattice structure. Almost all metals can form amalgams with mercury, the notable exceptions being iron, platinum, tungsten, and tantalum. Silver-mercury amalgams are important in dentistry, and gold-mercury amalgam is used in the extraction of gold from ore. Zinc amalgam finds use in"
"gas. Since the molecules present have been changed, this is a chemical change, similar to an intrinsic change. Sulfur-mercury theory of metals One of the goals of ""Theorica et practica"" is to affirm the validity of the sulfur-mercury theory of metals, which basically states that metals are composed of sulfur and mercury and the different proportions between the two form different types of metals. Observations of the reactivity of metals suggest that metals were in fact composed of sulfur and mercury. When metals were heated, they gave off a sulfurous odor. When mercury came in contact with metals such as"
"and inorganic salts. If not sealed off, mercury slowly evaporates into the air, forming a vapor. The quantity of vapor formed increases as temperatures rise. Elemental mercury is traditionally used in thermometers and some electrical switches. Inorganic mercury compounds or mercury salts, more commonly found in nature, include mercuric sulphide (HgS), mercuric oxide (HgO) and mercuric chloride (HgCl). Most of these are white powders or crystals, except for mercuric sulphide which is red and turns black after exposure to light. Organic mercury is formed when mercury combines with carbon and other elements. Examples of organic mercury compounds are dimethylmercury, phenylmercuric"
"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. Other mercury polycations are the linear and ions, and the triangular ion and a number of chain and layer polycations. The best known polycation of mercury is , in which mercury has a formal oxidation state of +1. The"
"fillings in permanent (adult) teeth. Mercury (element) Mercury is a chemical element with symbol Hg and atomic number 80. It is commonly known as quicksilver and was formerly named hydrargyrum ( ). A heavy, silvery d-block element, mercury is the only metallic element 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, gallium, and rubidium melt just above room temperature. Mercury occurs in deposits throughout the world mostly as cinnabar (mercuric sulfide). The red pigment vermilion is obtained by grinding natural cinnabar"
"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. Mercury(I) fluoride Mercury(I) fluoride or mercurous fluoride is the chemical compound composed of mercury and fluorine with the formula HgF. It consists of small yellow cubic crystals, which turn black when exposed to light. Mercury(I) fluoride is prepared by the reaction of"
"Mercury(I) iodide Mercury(I) iodide is a chemical compound of mercury and iodine. The chemical formula is HgI. It is photosensitive and decomposes easily to mercury and HgI. Mercury(I) iodide can be prepared by directly reacting mercury and iodine. In common with other Hg(I) (mercurous) compounds which contain linear X-Hg-Hg-X units, HgI contains linear IHgI units with an Hg-Hg bond length of 272 pm (Hg-Hg in the metal is 300 pm) and an Hg-I bond length of 268 pm. The overall coordination of each Hg atom is octahedral as it has in addition to the two nearest neighbours there are four"
"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. 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"
"long periods at elevated temperatures. It reverts to the elements upon heating near 400 °C, as was demonstrated by Joseph Priestley in an early synthesis of pure oxygen. Hydroxides of mercury are poorly characterized, as they are for its neighbors gold and silver. Being a soft metal, mercury forms very stable derivatives with the heavier chalcogens. Preeminent is mercury(II) sulfide, HgS, which occurs in nature as the ore cinnabar and is the brilliant pigment vermillion. Like ZnS, HgS crystallizes in two forms, the reddish cubic form and the black zinc blende form. The latter sometimes occurs naturally as metacinnabar. Mercury(II)"
"gold, silver, copper, tin, or lead, an amalgam resulted. These observations lead to the conclusion that metals were composed of both mercury and sulfur. Paul addresses one of the many arguments against the sulfur-mercury theory: that intermediate substances cannot exist between the pure elements and the “final product.” Therefore, metals cannot be broken down into sulfur and mercury. In ""Theorica et practica"", Paul first presents this argument before declining it in a contra and pro fashion. He first states the argument against the sulfur-mercury theory. Essentially the argument is as follows: In order to make “A” from “B and C”,"
"simple stable compounds with metal-metal bonds. Most mercury(I) compounds are diamagnetic and feature the dimeric cation, Hg. Stable derivatives include the chloride and nitrate. Treatment of Hg(I) compounds complexation with strong ligands such as sulfide, cyanide, etc. induces disproportionation to and elemental mercury. Mercury(I) chloride, a colorless solid also known as calomel, is really the compound with the formula HgCl, with the connectivity Cl-Hg-Hg-Cl. It is a standard in electrochemistry. It reacts with chlorine to give mercuric chloride, which resists further oxidation. Mercury(I) hydride, a colorless gas, has the formula HgH, containing no Hg-Hg bond. Indicative of its tendency to"
"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. Mercury selenide can also refer to the following chemical compounds: HgSe and HgSe. HgSe is strictly mercury(II) selenide. HgSe occurs naturally as the mineral Tiemannite. 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"
"(Medieval Latin amalgama, ""alloy of mercury"") with other metals. Alchemists thought of mercury as the First Matter from which all metals were formed. They believed that different metals could be produced by varying the quality and quantity of sulfur contained within the mercury. The purest of these was gold, and mercury was called for in attempts at the transmutation of base (or impure) metals into gold, which was the goal of many alchemists. Hg is the modern chemical symbol for mercury. It comes from ""hydrargyrum"", a Latinized form of the Greek word Ύδραργυρος (""hydrargyros""), which is a compound word meaning"
"Mercury(I) chloride Mercury(I) chloride is the chemical compound with the formula HgCl. Also known as the mineral calomel (a rare mineral) or mercurous chloride, this dense white or yellowish-white, odorless solid is the principal example of a mercury(I) compound. It is a component of reference electrodes in electrochemistry. The name calomel is thought to come from the Greek καλός ""beautiful"", and μέλας ""black""; or καλός and μέλι ""honey"" from its sweet taste. The ""black"" name (somewhat surprising for a white compound) is probably due to its characteristic disproportionation reaction with ammonia, which gives a “spectacular” black coloration due to the"
"traditionally used for tools.' In modern use, the term 'semimetal' sometimes refers, loosely or explicitly, to metals with incomplete metallic character in crystalline structure, electrical conductivity or electronic structure. Examples include gallium, ytterbium, bismuth, mercury and neptunium. Metalloids, which are in-between elements that are neither metals nor nonmetals, are also sometimes instead called semimetals. The elements commonly recognised as metalloids are boron, silicon, germanium, arsenic, antimony and tellurium. In old chemistry, before the publication in 1789 of Lavoisier's 'revolutionary' ""Elementary Treatise on Chemistry"", a semimetal was a metallic element with 'very imperfect ductility and malleability' such as zinc, mercury or"
"mercury had existed since the 1970s, and theoretical calculations in the 1990s predicted that it should be stable in the gas phase, with a square-planar geometry consistent with a formal d configuration. However, experimental proof remained elusive until 2007, when HgF was first prepared using solid neon and argon for matrix isolation at a temperature of 4 K. The compound was detected using infrared spectroscopy. Analysis of density functional theory and coupled cluster calculations showed that the d orbitals are involved in bonding, leading to the suggestion that mercury should be considered a transition metal after all. However, that conclusion"
"These are elements with a characteristic lustre such as iron, copper, and gold. Metals typically conduct electricity and heat well, and they are malleable and ductile. Around a dozen elements, such as carbon, nitrogen, and oxygen, are classified as non-metals. Non-metals lack the metallic properties described above, they also have a high electronegativity and a tendency to form negative ions. Certain elements such as silicon sometimes resemble metals and sometimes resemble non-metals, and are known as metalloids. A pure chemical compound is a chemical substance that is composed of a particular set of molecules or ions. Two or more elements"
"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. HgTe occurs in nature as the mineral form coloradoite. All properties are at standard temperature and pressure unless stated otherwise. The lattice parameter is about 0.646 nm in the cubic crystalline form. The bulk modulus is about 42.1 GPa. The thermal expansion coefficient is about 5.2×10/K. Static dielectric constant 20.8, dynamic dielectric constant 15.1. Thermal conductivity is low at 2.7 W·m/(m·K). HgTe bonds are weak leading"
"absorb mercury (spill kits also use activated carbon and powdered zinc). Mercury dissolves many other metals such as gold and silver to form amalgams. Iron is an exception, and iron flasks have traditionally been used to trade mercury. Several other first row transition metals with the exception of manganese, copper and zinc are reluctant to form amalgams. Other elements that do not readily form amalgams with mercury include platinum. Sodium amalgam is a common reducing agent in organic synthesis, and is also used in high-pressure sodium lamps. Mercury readily combines with aluminium to form a mercury-aluminium amalgam when the two"
"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. 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. Mercury selenide can also refer to the following chemical compounds: HgSe and HgSe. HgSe is strictly mercury(II) selenide. HgSe occurs naturally as the mineral Tiemannite. Along with other II-VI compounds,"
"Mercury(II) chloride Mercury(II) chloride or mercuric chloride (archaically, corrosive sublimate) is the chemical compound of mercury and chlorine with the formula HgCl. This white crystalline solid is a laboratory reagent and a molecular compound. Once used as a treatment for syphilis, it is no longer used for medicinal purposes because of mercury toxicity and the availability of superior treatments. Mercuric chloride exists not as a salt composed of discrete ions, but rather is composed of linear triatomic molecules, hence its tendency to sublime. In the crystal, each mercury atom is bonded to two close chloride ligands with Hg—Cl distance of"
"below 35 K. Cadmium is used in many kinds of solder and bearing alloys, due to a low coefficient of friction and fatigue resistance. It is also found in some of the lowest-melting alloys, such as Wood's metal. Because it is a liquid, mercury dissolves other metals and the alloys that are formed are called amalgams. For example, such amalgams are known with gold, zinc, sodium, and many other metals. Because iron is an exception, iron flasks have been traditionally used to trade mercury. Other metals that do not form amalgams with mercury include tantalum, tungsten and platinum. Sodium amalgam"
"result. Like Zosimos, Jabir believed this would require a catalyst, an ""al-iksir"", the elusive elixir that would make this transformation possible — which in European alchemy became known as the philosopher's stone. According to Jabir's mercury-sulfur theory, metals differ from each in so far as they contain different proportions of the sulfur and mercury. These are not the elements that we know by those names, but certain principles to which those elements are the closest approximation in nature. Based on Aristotle's ""exhalation"" theory the dry and moist exhalations become ""sulfur"" and ""mercury"" (sometimes called ""sophic"" or ""philosophic"" mercury and sulfur)."
"the real compound mercury(I) chloride (calumel), . The latter is an ionic compound with the dimercury(I) cation, or Hg–Hg, and chloride anions . However, like cinnabar, may be a covalent polymer rather than an ionic compound. Many stable polymeric mercury compounds with the bonding system E-Hg-Hg-E (E = N,P,As,Sb,O,S,Se,Sn) have been described since 1958. One may also note that the stable compound , recently synthesized, was found to consist of two-dimensional polymeric cations [–(S–)–Hg–Hg–(S–Hg–)–Hg– balanced by one-dimensional polymeric anions [––. In the cations, the sulfur atoms are trivalent, and the mercury atoms are divalent. In each unit, two of the"