is pure gold an element or a compound
chemical element
156794
Gold Gold is a chemical element with symbol Au (from ) and atomic number 79, making it one of the higher atomic number elements that occur naturally. In its purest form, it is a bright, slightly reddish yellow, dense, soft, malleable, and ductile metal. Chemically, gold is a transition metal and a group 11 element. It is one of the least reactive chemical elements and is solid under standard conditions. Gold often occurs in free elemental (native) form, as nuggets or grains, in rocks, in veins, and in alluvial deposits. It occurs in a solid solution series with the native
Gold
61349
different mass numbers are known as isotopes. For example, all atoms with 6 protons in their nuclei are atoms of the chemical element carbon, but atoms of carbon may have mass numbers of 12 or 13. The standard presentation of the chemical elements is in the periodic table, which orders elements by atomic number. The periodic table is arranged in groups, or columns, and periods, or rows. The periodic table is useful in identifying periodic trends. A "compound" is a pure chemical substance composed of more than one element. The properties of a compound bear little similarity to those of
Chemistry
9786632
regard. A chemical substance may well be defined as "any material with a definite chemical composition" in an introductory general chemistry textbook. According to this definition a chemical substance can either be a pure chemical element or a pure chemical compound. But, there are exceptions to this definition; a pure substance can also be defined as a form of matter that has both definite composition and distinct properties. The chemical substance index published by CAS also includes several alloys of uncertain composition. Non-stoichiometric compounds are a special case (in inorganic chemistry) that violates the law of constant composition, and for
Chemical substance
12981515
Chemical compound A chemical compound is a chemical substance composed of many identical molecules (or molecular entities) composed of atoms from more than one element held together by chemical bonds. A chemical element bonded to an identical chemical element is not a chemical compound since only one element, not two different elements, is involved. There are four types of compounds, depending on how the constituent atoms are held together: A chemical formula is a way of expressing information about the proportions of atoms that constitute a particular chemical compound, using the standard abbreviations for the chemical elements, and subscripts to
Chemical compound
12981525
compounds, and then bonds are reformed so that new associations are made between atoms. Schematically, this reaction could be described as , where A, B, C, and D are each unique atoms; and AB, AD, CD, and CB are each unique compounds. Chemical compound A chemical compound is a chemical substance composed of many identical molecules (or molecular entities) composed of atoms from more than one element held together by chemical bonds. A chemical element bonded to an identical chemical element is not a chemical compound since only one element, not two different elements, is involved. There are four types
Chemical compound
373990
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. Silver has long been valued as a precious metal. Silver
Silver
374271
Sulfur Sulfur or sulphur is a chemical element with symbol S and atomic number 16. It is abundant, multivalent, and nonmetallic. Under normal conditions, sulfur atoms form cyclic octatomic molecules with a chemical formula S. Elemental sulfur is a bright yellow crystalline solid at room temperature. Chemically, sulfur reacts with all elements except for gold, platinum, iridium, tellurium, and the noble gases. Sulfur is the tenth most common element by mass in the universe, and the fifth most common on Earth. Though sometimes found in pure, native form, sulfur on Earth usually occurs as sulfide and sulfate minerals. Being abundant
Sulfur
1284037
of the pure solvent, and the boiling-point elevation (Δ"T") is directly proportional to the amount concentration for dilute solutions. When the composition is expressed as a molality, the proportionality constant is known as the ebullioscopic constant ("K") and is characteristic for each solvent. If "w" represents the mass fraction of the solute in solution, and assuming no dissociation of the solute, the molar mass is given by Molar mass In chemistry, the molar mass "M" is a physical property defined as the mass of a given substance (chemical element or chemical compound) divided by the amount of substance. The base
Molar mass
14985152
triple point of water (273.16 K and 0.01 °C), it is impractical to use this definition at temperatures that are very different from the triple point of water. Accordingly, ITS–90 uses numerous defined points, all of which are based on various thermodynamic equilibrium states of fourteen pure chemical elements and one compound (water). Most of the defined points are based on a phase transition; specifically the melting/freezing point of a pure chemical element. However, the deepest cryogenic points are based exclusively on the vapor pressure/temperature relationship of helium and its isotopes whereas the remainder of its cold points (those less
Scale of temperature
1533333
electrodes, platinum-resistance thermometers, dentistry equipment, and jewelry. Because only a few hundred tonnes are produced annually, it is a scarce material, and is highly valuable and is a major precious metal commodity. Being a heavy metal, it leads to health issues upon exposure to its salts, but due to its corrosion resistance, it is not as toxic as some metals. Its compounds, most notably cisplatin, are applied in chemotherapy against certain types of cancer. Gold is a dense, soft, shiny, malleable and ductile metal. It is a chemical element with the symbol Au and atomic number 79. Pure gold has
Period 6 element
15219418
bonds than atoms. A molecule containing one or more rings is called a cyclic compound, and a molecule containing two or more rings (either in the same or different ring systems) is termed a polycyclic compound. A molecule containing no rings is called an acyclic or open-chain compound. A homocycle or homocyclic ring is a ring in which all atoms are of the same chemical element. A heterocycle or heterocyclic ring is a ring containing atoms of at least two different elements, i.e. a non-homocyclic ring. A carbocycle or carbocyclic ring is a homocyclic ring in which all of the
Ring (chemistry)
4835622
of which are based on various thermodynamic equilibrium states of fourteen pure chemical elements and one compound (water). Most of the defined points are based on a phase transition; specifically the melting/freezing point of a pure chemical element. However, the deepest cryogenic points are based exclusively on the vapor pressure/temperature relationship of helium and its isotopes whereas the remainder of its cold points (those less than room temperature) are based on triple points. Examples of other defining points are the triple point of hydrogen (−259.3467 °C) and the freezing point of aluminium (660.323 °C). Thermometers calibrated per ITS–90 use complex
International Temperature Scale of 1990
9026728
of the resulting gas mixture shows that it definitely contains chemical bonds, albeit very weak ones; thus, it is argon fluorohydride, and not a supermolecule or a mixture of argon and hydrogen fluoride. Its chemical bonds are stable only if the substance is kept at temperatures below 17 K (−256 °C); upon warming, it decomposes into argon and hydrogen fluoride. Argon fluorohydride Argon fluorohydride (systematically named fluoridohydridoargon) or argon hydrofluoride is an inorganic compound with the chemical formula HArF (also written ArHF). It is a compound of the chemical element argon. The discovery of this argon compound is credited to
Argon fluorohydride
10206
Arsenic Arsenic is a chemical element with symbol As and atomic number 33. Arsenic occurs in many minerals, usually in combination with sulfur and metals, but also as a pure elemental crystal. Arsenic is a metalloid. It has various allotropes, but only the gray form, which has a metallic appearance, is important to industry. The primary use of arsenic is in alloys of lead (for example, in car batteries and ammunition). Arsenic is a common n-type dopant in semiconductor electronic devices, and the optoelectronic compound gallium arsenide is the second most commonly used semiconductor after doped silicon. Arsenic and its
Arsenic
1402644
electrical contacts and the production of thick-film resistors. A minor application of ruthenium is its use in some platinum alloys. Rhodium is a chemical element that is a rare, silvery-white, hard, and chemically inert transition metal and a member of the platinum group. It has the chemical symbol Rh and atomic number 45. It is composed of only one isotope,Rh. Naturally occurring rhodium is found as the free metal, alloyed with similar metals, and never as a chemical compound. It is one of the rarest precious metals and one of the most costly (gold has since taken over the top
Period 5 element
5744794
production of one mole of gaseous atoms. When the atoms in the molecule are different isotopes of the same element the calculation becomes non-trivial. Standard enthalpy of atomization is the enthalpy change when 1 mol of a substance is dissociated completely into atoms under standard conditions (298.15K, 1 bar). Enthalpy of atomization The enthalpy of atomization (also atomisation in British spelling) is the enthalpy change that accompanies the total separation of all atoms in a chemical substance (either a chemical element or a chemical compound). This is often represented by the symbol Δ"H" or Δ"H". All bonds in the compound
Enthalpy of atomization
13250669
element in everyday use. Some are averse to collecting the element as a compound or alloy, while others find this acceptable. Collectors may isolate elements in their own homes. Hydrogen, for example, can be easily isolated via the electrolysis of water. In addition to the element samples, some element collectors also collect items connected with the element, such as manufactured goods containing the element, rocks and minerals with the element as a constituent or compounds of the element. Some manufacturers also sell coins made from pure elements, and density cubes made from the pure element can also be sourced on
Element collecting
69056
same atomic number, or number of protons. Nuclear scientists, however, define a pure element as one that consists of only one stable isotope. For example, a copper wire is 99.99% chemically pure if 99.99% of its atoms are copper, with 29 protons each. However it is not isotopically pure since ordinary copper consists of two stable isotopes, 69% Cu and 31% Cu, with different numbers of neutrons. However, a pure gold ingot would be both chemically and isotopically pure, since ordinary gold consists only of one isotope, Au. Atoms of chemically pure elements may bond to each other chemically in
Chemical element
1604309
is referenced in the Bible as brimstone in English, with this name still used in several nonscientific terms. Sulfur was considered important enough to receive its own alchemical symbol. It was needed to make the best quality of black gunpowder, and the bright yellow powder was hypothesized by alchemists to contain some of the properties of gold, which they sought to synthesize from it. In 1777, Antoine Lavoisier helped convince the scientific community that sulfur was a basic element, rather than a compound. Elemental sulfur was once extracted from salt domes where it sometimes occurs in nearly pure form, but
Period 3 element
12981517
of atoms (chemical elements) in a fixed stoichiometric proportion can be termed a "chemical compound"; the concept is most readily understood when considering pure chemical substances. It follows from their being composed of fixed proportions of two or more types of atoms that chemical compounds can be converted, via chemical reaction, into compounds or substances each having fewer atoms. The ratio of each element in the compound is expressed in a ratio in its chemical formula. A chemical formula is a way of expressing information about the proportions of atoms that constitute a particular chemical compound, using the standard abbreviations
Chemical compound
26689
compound in a sample is too high for the detection range of the technique, it can simply be diluted in a pure solvent. If the amount in the sample is below an instrument's range of measurement, the method of addition can be used. In this method a known quantity of the element or compound under study is added, and the difference between the concentration added, and the concentration observed is the amount actually in the sample. Sometimes an internal standard is added at a known concentration directly to an analytical sample to aid in quantitation. The amount of analyte present
Analytical chemistry
984148
(1170.4 kJ/mol), low electron affinity (estimated at −80 kJ/mol), and high electronegativity (2.4 AR). It forms a relatively large number of compounds, mostly containing fluorine or oxygen. An unusual ion containing xenon is the tetraxenonogold(II) cation, , which contains Xe–Au bonds. This ion occurs in the compound , and is remarkable in having direct chemical bonds between two notoriously unreactive atoms, xenon and gold, with xenon acting as a transition metal ligand. The compound contains a Xe–Xe bond, the longest element-element bond known (308.71 pm = 3.0871 Å). The most common oxide of xenon (XeO) is strongly acidic. Radon, which
Nonmetal
2699460
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
Group 12 element
2543713
are used in the function of excimer lasers. Recently, xenon has been shown to produce a wide variety of compounds of the type XeOX where "n" is 1,2 or 3 and X is any electronegative group, such as CF, C(SOCF), N(SOF), N(SOCF), OTeF, O(IOF), etc.; the range of compounds is impressive, similar to that seen with the neighbouring element iodine, running into the thousands and involving bonds between xenon and oxygen, nitrogen, carbon, boron and even gold, as well as perxenic acid, several halides, and complex ions. The compound XeSbF contains a Xe–Xe bond, which is the longest element-element bond
Noble gas compound
5999744
Peak, or the gabbro comprising Cuyamaca Peak. As these bedrocks weather, they become the parent material of the coarse, acidic, red soil found throughout the area. Gabbro weathers to a darker red soil than granodiorite or other quartz-rich rock. Gold is a natural element that appears around granite formations because gold forms during cooling and solidification of igneous rock. Gold commonly occurs in association with quartz, either as pure gold or as an ore. In the Cuyamaca area, gold is associated with the metasediment called Julian Schist. At mines in this area, including the Stonewall, veins of gold were followed
Cuyamaca Rancho State Park
1294720
to the three valence electrons that all of these elements, without exception, have in their valence shells. Boron was known to the ancient Egyptians, but only in the mineral borax. The metalloid element was not known in its pure form until 1808, when Humphry Davy was able to extract it by the method of electrolysis. Davy devised an experiment in which he dissolved a boron-containing compound in water and sent an electric current through it, causing the elements of the compound to separate into their pure states. To produce larger quantities he shifted from electrolysis to reduction with sodium. Davy
Boron group
9061709
phase transitions are called "latent" heats (for example, "latent heat of fusion"). An enthalpy change occurs during a chemical reaction. For the special case of the formation of a compound from the elements, the change is designated Δ"H" and is a weak function of temperature. Values of Δ"H" are usually given where the elements and compound are in their normal standard states, and as such are designated "standard heats" of formation, as designated by a superscript °. The Δ"H"° undergoes discontinuities at a phase transition temperatures of the constituent element(s) and the compound. The enthalpy change for any standard reaction
Thermodynamic databases for pure substances
305304
Oxide An oxide is a chemical compound that contains at least one oxygen atom and one other element in its chemical formula. "Oxide" itself is the dianion of oxygen, an O atom. Metal oxides thus typically contain an anion of oxygen in the oxidation state of −2. Most of the Earth's crust consists of solid oxides, the result of elements being oxidized by the oxygen in air or in water. Hydrocarbon combustion affords the two principal carbon oxides: carbon monoxide and carbon dioxide. Even materials considered pure elements often develop an oxide coating. For example, aluminium foil develops a thin
Oxide
9427245
known as 'purple death' or Roberts-Austen's 'purple gold') is a brittle, bright-purple compound, AuAl, or about 78.5%Au-21.5%Al by mass. AuAl is the most stable thermally of the Au-Al intermetallic compounds, with a melting point of 1060°C (see phase diagram), similar to that of pure gold. The process of the growth of the intermetallic layers causes reduction in volume, and hence creates cavities in the metal near the interface between gold and aluminium. Other gold-aluminium intermetallics can cause problems as well. Below 624°C, purple plague is replaced by AuAl, a tan-colored substance. It is a poor conductor and can cause electrical
Gold-aluminium intermetallic
467399
xenon is directly bonded to a less electronegative element than fluorine or oxygen, particularly carbon. Electron-withdrawing groups, such as groups with fluorine substitution, are necessary to stabilize these compounds. Numerous such compounds have been characterized, including: Other compounds containing xenon bonded to a less electronegative element include and . The latter is synthesized from dioxygenyl tetrafluoroborate, , at −100 °C. An unusual ion containing xenon is the tetraxenonogold(II) cation, , which contains Xe–Au bonds. This ion occurs in the compound , and is remarkable in having direct chemical bonds between two notoriously unreactive atoms, xenon and gold, with xenon acting
Xenon
240364
ideal formula is FeO, but due to crystallographic vacancies it is reduced to about FeO. In general, Proust's measurements were not accurate enough to detect such variations. In addition, the isotopic composition of an element can vary depending on its source, hence its contribution to the mass of even a pure stoichiometric compound may vary. This variation is used in geochemical dating since astronomical, atmospheric, oceanic, crustal and deep Earth processes may concentrate lighter or heavier isotopes preferentially. With the exception of hydrogen and its isotopes, the effect is usually small, but is measurable with modern instrumentation. An additional note:
Law of definite proportions
9061714
of a substance "H"("T") is defined in terms of its formation enthalpy and its heat content as follows: For an element, "H"("T") and ["H" - "H"] are identical at all temperatures because Δ"H"° is zero, and of course at 298.15 K, "H"("T") = 0. For a compound: Similarly, the absolute Gibbs energy "G"("T") is defined by the absolute enthalpy and entropy of a substance: For a compound: Some tables may also contain the Gibbs energy function ("H"° – "G"°)/"T" which is defined in terms of the entropy and heat content. The Gibbs energy function has the same units as entropy,
Thermodynamic databases for pure substances
8628322
brass, bronze, pewter, German silver, osmiridium, electrum, white gold, and silver-mercury and gold-mercury amalgam. Only gold, silver, copper and the platinum metals occur in nature in large amounts. Over geological time scales, very few metals can resist natural weathering processes like oxidation, which is why generally only the less reactive metals such as gold and platinum are found as native metals. The others usually occur as isolated pockets where a natural chemical process reduces a common compound or ore of the metal, leaving the pure metal behind as small flakes or inclusions. Non-metallic elements occurring in the native state include
Native metal
69072
meaning "no life") for "nitrogen". For purposes of international communication and trade, the official names of the chemical elements both ancient and more recently recognized are decided by the International Union of Pure and Applied Chemistry (IUPAC), which has decided on a sort of international English language, drawing on traditional English names even when an element's chemical symbol is based on a Latin or other traditional word, for example adopting "gold" rather than "aurum" as the name for the 79th element (Au). IUPAC prefers the British spellings "aluminium" and "caesium" over the U.S. spellings "aluminum" and "cesium", and the U.S.
Chemical element
4265516
and is also the key element of Deity yoga since the 'deity' in the yoga is the yidam. Yidam is said to be a contraction of Tib. "yid-kyi-dam-tshig", meaning "samaya of mind"- in other words, the state of being indestructibly bonded with the inherently pure and liberated nature of mind. The Sanskrit word ' or ' a compound of "iṣṭa" (desired, liked, reverenced) + "devatā" (a deity or divine being) is a term associated with yidam in many popular books on Buddhist Tantra but has not been attested in any Buddhist tantric text in Sanskrit. The yidam appears as one
Yidam
7931863
where an element is already a compound itself, even if the whole compound expresses function or purpose. For example, "rakétaindító állvány" ’rocket launching platform’ is written as two words because of its compound first element, despite the fact that it is not the platform which launches the rocket, but it is only used for it, so a function is expressed. If a phrase (e.g. an adjective and a noun or a noun and a postposition) written in two words receives a derivational suffix, it will also be written in two words – except if the meaning is changed. However, if
Hungarian orthography
4534848
elemental form and element X is oxidized from the elemental form into a cation.<br> Some examples are: Note that if the reactant in elemental form is not the more reactive metal, then no reaction will occur. Some examples of this would be the reverse reactions to these: One anion replaces another. An anion is a negatively charged ion or a nonmetal. Written using generic symbol, it is: Element A has replaced Y (in the compound XY) to form a new compound XA and the free element Y. This is an oxidation-reduction reaction wherein element A is reduced from the elemental
Single displacement reaction
11261335
and "invisible infinite consciousness, which shines everywhere" as point to the view that nirvana is a kind of Absolute. A similar view was defended by M. Falk, who held that the nirvanic element, as an "essence" or pure consciousness, is immanent within samsara. M. Falk argues that the early Buddhist view of nirvana is that it is an "abode" or "place" of prajña, which is gained by the enlightened. This nirvanic element, as an "essence" or pure consciousness, is immanent within samsara. A similar view is also defended by C. Lindtner, who argues that in precanonical Buddhism Nirvana is: According
Nirvana (Buddhism)
3951271
or to do something,’ or an adjective such as "həyɔnɔ" ‘alive’ in the compound "həyɔnɔ tammɔ" ‘to survive,’ although prepositions such as "qɔr" ‘at,’ in the compound "qɔr tammɔ" ‘to be born to s.o.,’ are attested. In many of these compounds, the verbal element is a "light" verb, which serves only to indicate verbal inflections such as person, tense, mood, and aspect; the meaning of these compounds is primarily derived from the non-verbal element, which always precedes the verbal element. The most common light verbs are "əwad" ~ "əwod" ("ɔwed") ‘to do,’ "əhaw" ~ "əhow" ("ɔhew") ‘to give,’ "məhɔ" ~
Neo-Mandaic
14079827
is Hg 61.14, Te 38.86; Table 1 shows results from a chemical analyses reported by Vlasov on samples collected from two different locations. Because it is found with other telluride ores, it carries some other metals like gold and silver. In its pure form, it has the composition mentioned above. A little hard to identify, petzite which is hazardous could be mistaken for coloradoite, on the other hand, petzite is anisotropic as opposed to coloradoite being an isotropic mineral. It is a binary compound with the general formula AX. Coloradoite has a sphalerite structure also known as the "diamond" or
Coloradoite
722607
early 1990s. This work led directly to the production of new isotopes of elements 112 to 118 in the reactions of Ca with actinide targets and the discovery of the 5 heaviest elements on the periodic table: flerovium, moscovium, livermorium, tennessine, and oganesson. In 1995, an international team led by Sigurd Hofmann at the Gesellschaft für Schwerionenforschung (GSI) in Darmstadt, Germany attempted to synthesise element 116 in a radiative capture reaction (in which the compound nucleus de-excites through pure gamma emission without evaporating neutrons) between a lead-208 target and selenium-82 projectiles. No atoms of element 116 were identified. In late
Livermorium
431786
as well. If belongs to and belongs to , then the equivalence class of is denoted by , which is called the tensor product of with . In physics and engineering, this use of the symbol refers specifically to the outer product operation; the result of the outer product is one of the standard ways of representing the equivalence class . An element of that can be written in the form is called a "pure" or "simple tensor". In general, an element of the tensor product space is not a pure tensor, but rather a finite linear combination of pure
Tensor product
11384983
Digallane Digallane (systematically named digallane(6) and di-μ-hydrido-bis(dihydridogallium)) is an inorganic compound with the chemical formula (also written or ). It is the dimer of the monomeric compound gallane. The eventual preparation of the pure compound, reported in 1989, was hailed as a "tour de force." Digallane had been reported as early as 1941 by Wiberg; however, this claim could not be verified by later work by Greenwood and others. A two-stage approach proved to be the key to successful synthesis of pure digallane. Firstly the dimeric monochlorogallane, (HGaCl) (containing bridging chlorine atoms and thus formulated as (HGa(μ-Cl))) was prepared via
Digallane
1762055
usually copper or aluminum. This is the so-called "ball bond" that gives the process its name. (All-aluminum systems in semiconductor fabrication eliminate the "purple plague"—a brittle gold-aluminum intermetallic compound—sometimes associated with pure gold bonding wire. This property makes aluminum ideal for ultrasonic bonding.) Next the wire is passed out through the capillary and the machine moves over a few millimeters to the location that the chip needs to be wired up to (usually called the "leadframe"). The machine again descends to the surface, this time without making a ball so that the wire is crushed between the leadframe and the
Ball bonding
17380267
example, a gold ingot identified as being .999 fine will be 999/1000 pure gold, with the other 1/1000 being impurities. Karat weight (K or kt) is a traditional fraction-based system used to denote the fineness of gold, with one karat being equal to 1/24 part of pure gold in an alloy. With the precision of modern assaying techniques, however, the fineness of gold ingots and bullion is more likely to appear as a decimal measurement. In this system, pure gold would be denoted as 1.000 fine. However, since absolutely pure gold is very soft and therefore not suitable for coinage
Gold coin
69055
whole number. For example, the relative atomic mass of chlorine is 35.453 u, which differs greatly from a whole number as it is an average of about 76% chlorine-35 and 24% chlorine-37. Whenever a relative atomic mass value differs by more than 1% from a whole number, it is due to this averaging effect, as significant amounts of more than one isotope are naturally present in a sample of that element. Chemists and nuclear scientists have different definitions of a "pure element". In chemistry, a pure element means a substance whose atoms all (or in practice almost all) have the
Chemical element
984165
made of almost pure antimony. Albertus Magnus (Albert the Great, 1193–1280) is believed to have been the first to isolate the element from a compound in 1250, by heating soap together with arsenic trisulfide. It so, it was the first element to be chemically discovered. Phosphorus was prepared from urine, by Hennig Brand, in 1669. Hydrogen: Cavendish, in 1766, was the first to distinguish hydrogen from other gases, although Paracelsus around 1500, Robert Boyle (1670), and Joseph Priestley (?) had observed its production by reacting strong acids with metals. Lavoisier named it in 1793. Oxygen: Carl Wilhelm Scheele obtained oxygen
Nonmetal
1761918
fine sizes and higher pull-test strengths in finished devices. Pure aluminum and 0.5% magnesium-aluminum are most commonly used in sizes larger than 0.004 inch (101 micrometer). All-aluminum systems in semiconductor fabrication eliminate the "purple plague" (brittle gold-aluminum intermetallic compound) sometimes associated with pure gold bonding wire. Aluminum is particularly suitable for thermosonic bonding. In order to assure that high quality bonds can be obtained at high production speeds, special controls are used in the manufacture of 1% silicon-aluminum wire. One of the most important characteristics of high grade bonding wire of this type is homogeneity of the alloy system. Homogeneity
Wire bonding
7395978
Palladium(II) cyanide Palladium(II) cyanides are chemical species with the empirical formula Pd(CN). The dicyanide ("n" = 2, CAS: [2035-66-7]) is a coordination polymer and was the first pure palladium compound isolated. In his attempts to produce pure platinum metal in 1804, W.H. Wollaston added mercuric cyanide to a solution of impure platinum metal in aqua regia. This precipitated palladium cyanide which was then ignited to recover palladium metal - a new element. It had long been suspected that the structure of palladium cyanide consists of square planar Pd(II) centers linked by bridging cyanide ligands, which are bonded through both the
Palladium(II) cyanide
2699475
(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
Group 12 element
4534847
silver, Ag, and zinc nitrate, Zn(NO) (which contains a Zn ion). All simple metal with acid reactions are single displacement reactions. For example, the reaction between magnesium, Mg, and hydrochloric acid, HCl, forms magnesium chloride, MgCl, and hydrogen, H. One cation replaces another. A cation is a positively charged ion or a metal. When it is written in generic symbols, it is written out like this: Element X has replaced Y in compound YZ to become a new compound XZ and the free element Y. This is an oxidation–reduction reaction wherein element Y is reduced from a cation into the
Single displacement reaction
922518
element. It involves weighing the compound both in air and in water, since weights are easier to measure exactly than volumes. By repeating the same with both gold and silver one finds exactly how much heavier than water gold, silver and the compound were. This treatise was extensively examined by Eilhard Wiedemann who believed that Khayyam's solution was more accurate and sophisticated than that of Khazini and Al-Nayrizi who also dealt with the subject elsewhere. Another short treatise is concerned with music theory in which he discusses the connection between music and arithmetic. Khayyam's contribution was in providing a systematic
Omar Khayyam
13600939
recrystallize using any of the methods listed above. Crystallization requires an initiation step. This can be spontaneous or can be done by adding a small amount of the pure compound (a seed crystal) to the saturated solution, or can be done by simply scratching the glass surface to create a seeding surface for crystal growth. It is thought that even dust particles can act as simple seeds. Growing crystals for X-ray crystallography can be quite difficult. For X-ray analysis, single perfect crystals are required. Typically a small amount (5–100 mg) of pure compound is used, and crystals are allowed to
Recrystallization (chemistry)
20244947
+ H2(g)') => #<Eulim::Chemistry::Reaction:0x00000002ce22f8 @equation="2Na(s) + 2HCl(aq) » 2NaCl(aq) + H2(g)", @species={:reactants=>{"Na"=>{:compound=>#<Eulim::Chemistry::Compound:0x00000002ce1d80 @formula="Na", @constituents={"Na"=>{:element=>#<Eulim::Chemistry::Element:0x00000002c88e10 @name="Sodium", @symbol="Na", @atomic_number=11, @atomic_mass=#<Unitwise::Measurement value=22.9897 unit=u», :atom_count=>1}}, @molecular_mass=#<Unitwise::Measurement value=22.9897 unit=u», :stoichiometry=>2, :state=>"solid"}, "HCl"=>{:compound=>#<Eulim::Chemistry::Compound:0x00000002cabdc0 @formula="HCl", @constituents={"H"=>{:element=>#<Eulim::Chemistry::Element:0x000000025e5ab8 @name="Hydrogen", @symbol="H", @atomic_number=1, @atomic_mass=#<Unitwise::Measurement value=1.0079 unit=u», :atom_count=>1}, "Cl"=>{:element=>#<Eulim::Chemistry::Element:0x00000002c82c90 @name="Chlorine", @symbol="Cl", @atomic_number=17, @atomic_mass=#<Unitwise::Measurement value=35.453 unit=u», :atom_count=>1}}, @molecular_mass=#<Unitwise::Measurement value=36.4609 unit=u», :stoichiometry=>2, :state=>"aqueous"}}, :products=>{"NaCl"=>{:compound=>#<Eulim::Chemistry::Compound:0x00000002c8cda8 @formula="NaCl", @constituents={"Na"=>{:element=>#<Eulim::Chemistry::Element:0x00000002c88e10 @name="Sodium", @symbol="Na", @atomic_number=11, @atomic_mass=#<Unitwise::Measurement value=22.9897 unit=u», :atom_count=>1}, "Cl"=>{:element=>#<Eulim::Chemistry::Element:0x00000002c82c90 @name="Chlorine", @symbol="Cl", @atomic_number=17, @atomic_mass=#<Unitwise::Measurement value=35.453 unit=u», :atom_count=>1}}, @molecular_mass=#<Unitwise::Measurement value=58.4427 unit=u», :stoichiometry=>2, :state=>"aqueous"},"H2"=>{:compound=>#<Eulim::Chemistry::Compound:0x00000002c6f938 @formula="H2", @constituents={"H"=>{:element=>#<Eulim::Chemistry::Element:0x000000025e5ab8 @name="Hydrogen", @symbol="H", @atomic_number=1, @atomic_mass=#<Unitwise::Measurement value=1.0079 unit=u», :atom_count=>2}}, @molecular_mass=#<Unitwise::Measurement value=2.0158 unit=u», :stoichiometry=>1, :state=>"gaseous"}}}, @is_valid=true, @is_balanced=true> Eulim Eulim is a Chemistry library written in Ruby under the MIT
Eulim
10386422
Kirk (placename element) Kirk is found as an element in many place names in Scotland, England, and North America. It is derived from "kirk", meaning "church". In Scotland, it is sometimes an English translation from a Scots Gaelic form involving "cille" or "eaglais", both words for 'church'. Rarely it is found in Anglicisations of Continental European placenames which originally had Dutch "kerk" or a related form. Kirk by itself is the name of two places: More usually it is an element in a compound name. The remainder of this article is a list of some of these. In Scotland In
Kirk (placename element)
11581835
"pure" they have varying tensile strength among other differences. These differences are caused by the amount of interstitial elements present in the titanium. Interstitial element An interstitial element is an impurity found in "pure" metals or crystals. The quantity of these elements affect the physical properties of the host material. They can be introduced during the manufacturing process. The most common interstitial elements in metals are hydrogen, carbon, nitrogen, and oxygen. These elements are small enough to fit between normal crystalline lattice locations. In contrast, those elements that replace locations in the crystalline structure are called substitutional elements. An example
Interstitial element
1604303
its discovery: silicon was first prepared and characterized in pure form in 1824, and given the name silicium (from , flints), with an -ium word-ending to suggest a metal. However, its final name, suggested in 1831, reflects the more physically similar elements carbon and boron. Silicon is the eighth most common element in the universe by mass, but very rarely occurs as the pure free element in nature. It is most widely distributed in dusts, sands, planetoids, and planets as various forms of silicon dioxide (silica) or silicates. Over 90% of the Earth's crust is composed of silicate minerals, making
Period 3 element
48674
liquid is the highest temperature (and pressure) it will actually boil at. See also Vapour pressure of water. The element with the lowest boiling point is helium. Both the boiling points of rhenium and tungsten exceed 5000 K at standard pressure; because it is difficult to measure extreme temperatures precisely without bias, both have been cited in the literature as having the higher boiling point. As can be seen from the above plot of the logarithm of the vapor pressure vs. the temperature for any given pure chemical compound, its normal boiling point can serve as an indication of that
Boiling point
78042
pure element) to +1: in other words, the sodium lost one electron and is said to have been oxidized. On the other hand, the chlorine gas goes from an oxidation of 0 (it is also a pure element) to −1: the chlorine gains one electron and is said to have been reduced. Because the chlorine is the one reduced, it is considered the electron acceptor, or in other words, induces oxidation in the sodium – thus the chlorine gas is considered the oxidizing agent. Conversely, the sodium is oxidized or is the electron donor, and thus induces reduction in the
Chemical reaction
3859005
languages are commonly referred to as "coverbs". A distinction is sometimes made between serial verbs and compound verbs (also known as "complex predicates"). In a compound verb, the first element (verb or noun) generally carries most of the semantic load, while the second element, often called a "vector verb" (light verb) or "explicator verb", provides fine distinctions (such as speaker attitude or grammatical aspect) and carries the inflection (markers of tense, mood and agreement). The first element may be a verb in conjunctive participle form, or as in Hindi and Punjabi, a bare verbstem). For example, Hindi: In this example,
Serial verb construction
20666563
aniline. However, Pd-Au/AlO (Au/Pd ≥20) has been proven thrice as active as the pure Au catalyst, while being ~100% selective to "p"-chloroaniline. In a mechanistic study of hydrogenation of nitrobenzenes with Pt-Au/TiO, the dissociation of H was identified as rate-controlling, hence the incorporation of Pt, an efficient hydrogenation metal, highly improved catalytic activity. Dihydrogen dissociated on Pt and the nitroaromatic compound was activated on the Au-TiO interface. Finally, hydrogenation was enabled by the spillover of activated H surface species from Pt to the Au surface. Heterogeneous gold catalysis Heterogeneous gold catalysis refers to the catalysis of chemical reactions by gold
Heterogeneous gold catalysis
8141702
Pure subgroup In mathematics, especially in the area of algebra studying the theory of abelian groups, a pure subgroup is a generalization of direct summand. It has found many uses in abelian group theory and related areas. A subgroup formula_1 of a (typically abelian) group formula_2 is said to be pure if whenever an element of formula_1 has an formula_4 root in formula_2, it necessarily has an formula_4 root in formula_1. Formally, formula_8 is solvable in formula_2 formula_10 is solvable in formula_1. Pure subgroups are also called isolated subgroups or serving subgroups and were first investigated in Prüfer's 1923 paper
Pure subgroup
20691437
·, or , as monoclinic crystals. This compound is less hygroscopic and less volatile than pure hydrazinium azide. It decomposes explosively into nitrogen, hydrogen, and ammonia. At pressure of 40 GPa, hydrazinium azide decomposes yielding a linear nitrogen allotrope or N≡——N=N——≡N, that decomposes to ε- below 25 GPa. Reaction of hydrazinium azide with sulfuric acid gives quantitative yields of pure hydrazinediium sulfate and hydrazoic acid: Hydrazinium azide Hydrazinium azide or hydrazine azide is a chemical compound with formula or . It is a salt of the hydrazinium cation and the azide anion . It can be seen as a derivative
Hydrazinium azide
9965048
Triethylaluminium Triethylaluminium is an organoaluminium compound. Despite its name, the formula for this compound is Al(CH), shortened to AlEt (Et, ethyl). This volatile, colorless liquid is highly pyrophoric, igniting immediately upon exposure to air. It is normally stored in stainless steel containers either as a pure liquid or as a solution in hydrocarbon solvents such as hexane, heptane, or toluene. Triethylaluminium is mainly used as a co-catalyst in the industrial production of polyethylene, polypropylene and for the production of medium chain alcohols. The compound is a dimer of triethylaluminium. One pair of ethyl groups bridge the two Al centers, and
Triethylaluminium
8145082
pure form, are often described as existing with a zero oxidation state. This is one of the attributes of nomenclature that has been upheld over the years. The chemical state of an element is often confused with its oxidation state. The chemical state of an element or a group of elements that has a non-zero ionic charge, e.g. (1+), (2+), (3+), (1-), (2-) (3-), is defined as the oxidation state of that element or group of elements. Elements or chemical groups that have an ionic charge can usually be dissolved to form ions in either water or another polar solvent.
Chemical state
9786640
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
Chemical substance
1294722
element. Many improvements followed, a significant advance being made just two years later by Friedrich Wöhler, whose slightly modified procedure still yielded an impure product. The first pure sample of aluminium is credited to Henri Etienne Sainte-Claire Deville, who substituted sodium for potassium in the procedure. At that time aluminium was considered precious, and it was displayed next to such metals as gold and silver. The method used today, electrolysis of aluminium oxide dissolved in cryolite, was developed by Charles Martin Hall and Paul Héroult in the late 1880s. Thallium, the heaviest stable element in the boron group, was discovered
Boron group
8102624
Diethylzinc Diethylzinc (CH)Zn, or DEZ, is a highly pyrophoric and reactive organozinc compound consisting of a zinc center bound to two ethyl groups. This colourless liquid is an important reagent in organic chemistry. It is available commercially as a solution in hexanes, heptane, or toluene, or as a pure liquid. Edward Frankland first reported the compound in 1848 from zinc and ethyl iodide, the first organozinc compound discovered. He improved the synthesis by using diethyl mercury as starting material The contemporary synthesis consists of the reaction of a 1:1 mixture of ethyl iodide and ethyl bromide with a zinc-copper couple,
Diethylzinc
12642920
Colored gold Pure gold is slightly reddish yellow in color, but colored gold in various other colors can be produced. Colored golds can be classified to three groups: Pure 100% (in practice, 99.9% or better) gold is 24 karat by definition, so all colored golds are less than this, with the common being 18K (75%), 14K (58.5%), 10K (41.6%), and 9K (37.5%). "White gold" is an alloy of gold and at least one white metal (usually nickel, manganese, or palladium). Like yellow gold, the purity of white gold is given in karats. White gold's properties vary depending on the metals
Colored gold
10749895
rule which assigns focus to an element in pre-verbal position. The affirmative use of "ba-" (not to confused with the homophonous subordinating prefix meaning 'if') is normally used with synthetic finite forms, thus also "John badator" or "Badator John" 'John is coming' (as opposed to "John dator" " 'John" is coming'), "Badu dirua" (or in western Basque "Badauka dirua") 'She has money'. In most varieties of Basque, affirmative "ba-" is not so used with compound tenses or compound verbs, however. To place a compound verb form (or its affirmation) in focus, it may be enough to place the main sentence
Basque grammar
6157686
Magic sand Magic sand or hydrophobic sand is a toy made from sand coated with a hydrophobic compound. The presence of this hydrophobic compound causes the grains of sand to adhere to one another and form cylinders (to minimize surface area) when exposed to water. When the sand is removed from water, it is completely dry and free flowing. Magic sand is also known as Aqua Sand. These properties are achieved with ordinary beach sand, which contains tiny particles of pure silica, and exposing it to vapors of trimethylsilanol (CH)SiOH, an organosilicon compound. Upon exposure, the trimethylsilane compound bonds to
Magic sand
9998471
Sanskrit compound One notable feature of the agglutinative nominal system of Classical Sanskrit is the very common use of nominal compounds ("samāsa"), which may be huge (10+ or even 30+ words) and are generative. Nominal compounds occur with various structures, but morphologically speaking they are essentially the same: each noun (or adjective) is in its (weak) stem form, with only the final element receiving case inflection. The first member of this type of nominal compound is an indeclinable, to which another word is added so that the new compound also becomes indeclinable (i.e., ). Examples: + ("per power"; as much
Sanskrit compound
1807886
this way. Such verbs comprise a small closed class. Borrowed words, which can be used as verbs by combining them with the auxiliary verb , do not occur as the second element in compound verbs. For example, the Sino-Japanese verb itself can be modified, as in , but it does not combine with another verb as its second or modifying element. Japanese "i"-adjectives, which function grammatically as non-finite verbs, can also compound, functioning as compound modifiers, but that is less common than for verbs. (See Japanese equivalents of adjectives for details.) Under the influence of a Kichwa substrate, speakers living
Compound verb
313395
because the platinum they experimented with was highly contaminated with minute amounts of platinum-family elements such as osmium and iridium, amongst others, which embrittled the platinum alloy. Alloying this impure platinum residue called "plyoxen" with gold was the only solution at the time to obtain a pliable compound, but nowadays, very pure platinum is available and extremely long wires can be drawn from pure platinum, very easily, due to its crystalline structure, which is similar to that of many soft metals. In 1786, Charles III of Spain provided a library and laboratory to Pierre-François Chabaneau to aid in his research
Platinum
1402650
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. Silver has long been valued as a precious metal, and it is used to make ornaments, jewelry, high-value tableware, utensils (hence the term "silverware"), and currency coins. Today, silver metal is also used in electrical contacts and conductors, in mirrors and in catalysis of chemical reactions. Its compounds are used in photographic film, and dilute silver nitrate solutions and
Period 5 element
18147829
Campa Cola Compound Case Campa Cola Compound Case is based on the judicial process and the controversy over the Campa Cola Compound, an apartment complex in the southern part of Worli in South Mumbai, India. The Campa Cola Compound was constructed on land leased to Pure Drinks Ltd in 1955, which was permitted by B.M.C in 1980 to develop it for residential purposes. Pure Drinks along with builders, Yusuf Patel, B.K. Gupta and P.S.B Construction Co erected seven buildings, two of which were high-rise buildings of 17 and 20 stories. During the construction period, the authorities issued notices to the
Campa Cola Compound Case
10123650
unaccented, with all the syllables on the same pitch. Suffixes such as "-di" and "-se/-sa" are not pre-accenting if they are added directly to the verb stem: This accentual pattern can disambiguate homographic words containing possessive suffixes or the plural suffix: Compound nouns are usually accented on the first element only. Any accent on the second element is lost, just as in English compounds such as "police-station", where the second element has no accent: The same is true of compound and intensive adjectives: Some compounds, however, are accented on the final, for example those of the form verb-verb or subject-verb:
Turkish phonology
4915053
change dramatically, whilst pure bromide papers change little. Fibre-based papers are more responsive to selenium toning. Selenium toning may not produce prints quite as stable as sepia or gold toning. Recently, doubts have surfaced as to the effectiveness of selenium toner in ensuring print longevity. Sepia toning is a specialized treatment to give a black-and-white photographic print a warmer tone and to enhance its archival qualities. The metallic silver in the print is converted to a sulfide compound, which is much more resistant to the effects of environmental pollutants such as atmospheric sulfur compounds. Silver sulfide is at least 50%
Photographic print toning
8242863
Gold(I,III) chloride Gold(I,III) chloride is a black solid with the chemical formula AuCl. It is an example of a mixed valence compound as it contains gold in two different oxidation states; square-planar gold(III) and almost linear gold(I). The compound must be handled carefully as it is photosensitive as well as extremely air and moisture sensitive. Gold(I,III) chloride may be prepared by the reaction of gold(III) chloride with gold carbonyl chloride or carbon monoxide at room temperature in thionyl chloride. Au(CO)Cl + AuCl → COCl + AuCl 2 AuCl + 2 CO → AuCl + 2 COCl Single crystals of gold(I,III)
Gold(I,III) chloride
6426677
1,4-Benzoquinone 1,4-Benzoquinone, commonly known as "para"-quinone, is a chemical compound with the formula CHO. In a pure state, it forms bright-yellow crystals with a characteristic irritating odor, resembling that of chlorine, bleach, and hot plastic or formaldehyde. This six-membered ring compound is the oxidized derivative of 1,4-hydroquinone. The molecule is multifunctional: it exhibits properties of a ketone, forming an oxime; an oxidant, forming the dihydroxy derivative; and an alkene, undergoing addition reactions, especially those typical for α,β-unsaturated ketones. 1,4-Benzoquinone is sensitive toward both strong mineral acids and alkali, which cause condensation and decomposition of the compound. 1,4-Benzoquinone is prepared industrially
1,4-Benzoquinone
4789145
called bonds, representing a saturated valency for each element. The two tables below show some examples of different compounds, their valence diagrams, and the valences for each element of the compound. Valence only describes connectivity; it does not describe the geometry of molecular compounds, or what are now known to be ionic compounds or giant covalent structures. A line between atoms does not represent a pair of electrons as it does in Lewis diagrams. Valence is defined by the IUPAC as: An alternative modern description is: This definition differs from the IUPAC definition as an element can be said to
Valence (chemistry)
10529748
N-rule (Icelandic language) In Icelandic orthography, the n-rules are rules for determining when one letter "n" or two consecutive "n"s should be written, a difference that sometimes affects the pronunciation. If an element of a compound word that is not the final element ends with one or two "n"s, the number of "n"s is the same as in the original word from which that element is derived, of which it is a possibly modified and usually shortened form. For example: It can be hard to find related words to determine whether one or two "n"s should be written. One way
N-rule (Icelandic language)
17547378
thus "surfitta" lit. "sour-cunt" may be understood either as "someone whose cunt is acidic" (thus a bahuvrihi compound) or "someone who is acidic like a cunt". The same ambiguity applies e.g. to "kukhuvud", like English "dickhead". Sometimes, when an element can be used as derogatory or intensifying in either prefixed and suffixed positions, the relation between elements in the compound can be reversed with basically no change in meaning, e.g. "idiotfitta" and "fittidiot" combining "idiot" and "cunt". One particular compounding construction takes the profanity as the head of the compound and the referent as the modifier: thus "hundjävel" means approximately
Swedish profanity
10117343
elsewhere. Pure 24 Karat gold bars, and stocks of pure silver and copper are the basic materials. These metals are not required to be mined in the Black Hills. Pure gold and other precious metal stock can be acquired from anywhere in the world. The finished jewelry known as Black Hills Gold must be "produced" in the Black Hills of South Dakota. The different colors of gold used for leaves and other details are made when the pure 24 Karat yellow gold is alloyed with copper to achieve the traditional 14 karat pink (or red) gold, and the gold is
Black Hills gold jewelry
13100549
Plumbides can also be Zintl phase compounds, such as [K(18-crown-6)]KPb·(en). This is not a simple Zintl compound, but rather contains the organic molecules 18-crown-6 and ethylenediamine (en) in order to stabilize the crystal structure. Plumbide A plumbide can refer to one of two things: an intermetallic compound that contains lead, or a Zintl phase compound with lead as the anion. Plumbides can be formed when lead forms a Zintl phase compound with a more metallic element. One salt that can be formed this way is when cryptand reacts with sodium and lead in ethylenediamine (en) to produce [Pb], which is
Plumbide
13100547
Plumbide A plumbide can refer to one of two things: an intermetallic compound that contains lead, or a Zintl phase compound with lead as the anion. Plumbides can be formed when lead forms a Zintl phase compound with a more metallic element. One salt that can be formed this way is when cryptand reacts with sodium and lead in ethylenediamine (en) to produce [Pb], which is red in solution. Lead can also create anions with tin, in a series of anions with the formula [SnPb]. Lead can also form the [Pb] anion, which is emerald green in solution. An example
Plumbide
1515738
destination. The dualism is therefore not absolute, and, though present in man's own constitution as composed of body and soul, is relative only even there. The ego is itself both body and soul — the conjunction of both constitutes it. Our "organization" or sense nature has its intellectual element, and our "intellect" its organic element, and there is no such thing as "pure mind" or "pure body." The one general function of the ego, thought, becomes in relation to the non-ego either receptive or spontaneous action, and in both forms of action its organic, or sense, and its intellectual energies
Friedrich Schleiermacher
8266878
Gold(V) fluoride Gold(V) fluoride is the inorganic compound with the formula AuF. This fluoride compound features gold in its highest known oxidation state. This red solid dissolves in hydrogen fluoride but these solutions decompose, liberating fluorine. The structure of gold(V) fluoride in the solid state is centrosymmetric with hexacoordinated gold and an octahedral arrangement of the fluoride centers on each gold center. It is the only known dimeric pentafluoride; other pentafluorides are monomeric (P, As, Cl, Br, I), tetrameric (Nb, Ta, Cr, Mo, W, Tc, Re, Ru, Os, Rh, Ir, Pt), or polymeric (Bi, V, U). In the gas phase,
Gold(V) fluoride
13197754
Cobalt(II) hydroxide Cobalt(II) hydroxide or cobaltous hydroxide is the inorganic compound with the formula , consisting of divalent cobalt cations and hydroxide anions . The pure compound, often called the "beta form" (β-) is a pink solid insoluble in water. The name is also applied to a related compound, often called "alpha" or "blue" form (α-), which incorporates other anions in its molecular structure. This compound is blue and rather unstable. Cobalt(II) hydroxide is most used as a drying agent for paints, varnishes, and inks, in the preparation of other cobalt compounds, as a catalyst and in the manufacture of
Cobalt(II) hydroxide
5419450
it "Rosölsäure" or "Rosaölsäure" (red oil acid). In 1861, the German chemists Hermann Kolbe and Rudolf Schmitt presented the synthesis of aurin by heating oxalic acid and creosote (which contains phenol) in the presence of concentrated sulfuric acid. (Gradually, chemists realized that commercial aurin was not a pure compound, but was actually a mixture of similar compounds.) Aurin is formed by heating of phenol and oxalic acid in concentrated sulfuric acid. Causes eye, skin, and respiratory tract irritation. Avoid ingestion and/ or inhalation. Aurin Aurin (C.I. 43800), sometimes named rosolic acid or corallin is an organic compound, forming yellowish or
Aurin
19066419
CD/DVD based immunoassay A compact disk/digital versatile disk (CD/DVD) based immunoassay is a method for determining the concentration of a compound in research and diagnostic laboratories by performing the test on an adapted CD/DVD surface using an adapted optical disc drive; these methods have been discussed and prototyped in research labs since 1991. CDs and DVDs have a polycarbonate surface and metal reflective layer which allow for storage and retrieval of information. The metal film is sometimes made of pure gold which is highly stable and has ideal optical properties. The metal can act as a substrate which allows compounds
CD/DVD based immunoassay
19066427
on bringing CD/DVD based immunoassays and equipment to market. CD/DVD based immunoassay A compact disk/digital versatile disk (CD/DVD) based immunoassay is a method for determining the concentration of a compound in research and diagnostic laboratories by performing the test on an adapted CD/DVD surface using an adapted optical disc drive; these methods have been discussed and prototyped in research labs since 1991. CDs and DVDs have a polycarbonate surface and metal reflective layer which allow for storage and retrieval of information. The metal film is sometimes made of pure gold which is highly stable and has ideal optical properties. The
CD/DVD based immunoassay
8732701
personality which constitutes an absolute element in this contingent world" as pointing to this. Influenced by Schayer, M. Falk argues that the early buddhist view of nirvana is that it is an "abode" or "place" of prajña, which is gained by the enlightened. This nirvanic element, as an "essence" or pure consciousness, is immanent within samsara. The three bodies are concentric realities, which are stripped away or abandoned, leaving only the nirodhakaya of the liberated person. A similar view is also defended by C. Lindtner, who argues that in precanonical Buddhism Nirvana is: According to Lindtner, Canonical Buddhism was a
Pre-sectarian Buddhism
4516750
detail: Raoult's law states that the partial pressure of component B is related to its vapor pressure (saturation pressure) and its mole fraction "x" in the liquid phase, with the convention formula_6 In other words: Pure liquids represent the ideal case. At infinite dilution, the activity coefficient approaches its limiting value, "γ". Comparison with Henry's law, immediately gives In other words: The compound shows nonideal behavior in the dilute case. The above definition of the activity coefficient is impractical if the compound does not exist as a pure liquid. This is often the case for electrolytes or biochemical compounds. In
Activity coefficient
8355466
Cinnamyl alcohol Cinnamyl alcohol or styron is an organic compound that is found in esterified form in storax, Balsam of Peru, and cinnamon leaves. It forms a white crystalline solid when pure, or a yellow oil when even slightly impure. It can be produced by the hydrolysis of storax. Cinnamyl alcohol has a distinctive odour described as "sweet, balsam, hyacinth, spicy, green, powdery, cinnamic" and is used in perfumery and as a deodorant. Cinnamyl alcohol is naturally occurrent only in small amount, so its industrial demand is usually fulfilled by chemical synthesis starting from cinnamaldehyde. The compound is a solid
Cinnamyl alcohol
12231838
Ditran Ditran (JB-329) is an anticholinergic drug mixture, related to the chemical warfare agent 3-Quinuclidinyl benzilate (QNB). Ditran is composed of a mixture of 70% 1-ethyl-2-pyrrolidinylmethyl-alpha- phenylcyclopentylglycolate and 30% 1-ethyl-3-piperidyl-alpha-phenylcyclopentylglycolate. These compounds are structural isomers and have very similar pharmacological properties. The piperidine compound is the more potent of the two and the reason the mixture was used was because of ease of manufacture, however it is also possible to make the piperidine compound in its pure form, so there were ultimately two forms of Ditran used in research, the original 70/30 mix, and "Ditran-B", the pure piperidine compound. Ditran
Ditran
12099497
Bromoxynil Bromoxynil is an organic compound with the formula HOBr2C6H2CN. It is classified as a nitrile herbicide, and as such sold under many trade names. It is a white solid. It works by inhibiting photosynthesis. It is moderately toxic to mammals. It is produced by bromination of 4-hydroxybenzonitrile. It is a post-emergence to control annual broadleaved weeds. Bromoxynil decomposes with a half life of approximately two weeks in soil. Persistence increases in soils with elevated clay or organic matter content, suggesting the compound has somewhat limited bioavailability to microorganisms in these environments. Under aerobic conditions in soils or pure cultures,
Bromoxynil
4534849
form into an anion and element Y is oxidized from an anion into the elemental form. Some of the few examples that involve halogens are shown here: Again, the less reactive halogen cannot replace the more reactive halogen: Single displacement reaction A single-displacement reaction, also known as a single-replacement reaction, is a reaction by which one (or more) element(s) replaces an/other element(s) in a compound. It can be represented generically as: This will most often occur if A is more reactive than B, thus giving a more stable product. A and B must be either: In either case, when AC
Single displacement reaction
4382199
gold (12 parts another metal), and so forth. In England, the karat was divisible into four grains, and the grain was divisible into four quarts. For example, a gold alloy of fineness (that is, 99.2% purity) could have been described as being "23-karat, 3-grain, 1-quart gold". The karat fractional system is increasingly being complemented or superseded by the millesimal system, described above. Conversion between percentage of pure gold and karats: However, this system of calculation gives only the mass of pure gold contained in an alloy. The term "18-karat gold" means that the alloy's mass consists of 75% of gold
Fineness
17763272
pronunciations. The two upper dots are then used to indicate whether this is a whole character, 木, or an element of a compound character. For a whole character, both upper dots are added, for 木 "ki". For a partial character, one upper dot is used: The left upper dot alone indicates the first (left, top, or outside) constituent part of a kanji, as in 村, and the right upper dot alone signals the final (right, bottom, or inside) constituent part of a kanji, as in 林. For those kanji where an element is repeated more than once, a suffix corresponding
Braille kanji
7123566
Mond process The Mond process, sometimes known as the carbonyl process, is a technique created by Ludwig Mond in 1890, to extract and purify nickel. The process was used commercially before the end of the 19th century. This process converts nickel oxides into pure nickel. This process involves the fact that carbon monoxide combines with nickel readily and reversibly to give nickel carbonyl. No other element forms a carbonyl compound under the mild conditions used in the process. This process has three steps: 1. Nickel oxide reacts with Syngas at 200 °C to give nickel, together with impurities including iron
Mond process