• metals
  • A relatively soft metal, gold is usually hardened by alloying with copper, silver, or other metals. (thefreedictionary.com)
  • thus gold containing 10% of other metals is said to have a fineness of 900. (thefreedictionary.com)
  • Gold is extracted from its ores by mechanical means and separated from other metals by chemical processes, notably the cyanide process cyanide process or cyanidation, method for extracting gold from its ore. (thefreedictionary.com)
  • Whereas most metals are gray or silvery white, gold is slightly reddish-yellow. (wikipedia.org)
  • This color is determined by the frequency of plasma oscillations among the metal's valence electrons, in the ultraviolet range for most metals but in the visible range for gold due to relativistic effects affecting the orbitals around gold atoms. (wikipedia.org)
  • 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. (wikipedia.org)
  • As a practical matter, when platinum group metals are purified through dissolution in aqua regia, gold (commonly associated with PGMs) is precipitated by treatment with iron(II) chloride. (wikipedia.org)
  • Platinum is more ductile than gold, silver or copper, thus being the most ductile of pure metals, but it is less malleable than gold. (wikipedia.org)
  • From this perspective, only copper, silver and gold are noble metals, as all d-like bands are filled and do not cross the Fermi level. (wikipedia.org)
  • The difference in reactivity can easily be seen during the preparation of clean metal surfaces in an ultra-high vacuum: surfaces of "physically defined" noble metals (e.g., gold) are easy to clean and keep clean for a long time, while those of platinum or palladium, for example, are covered by carbon monoxide very quickly. (wikipedia.org)
  • The noble metals ruthenium, rhodium, palladium, platinum, and gold react least readily, requiring pure fluorine gas at 300-450 °C (575-850 °F). Fluorine reacts explosively with hydrogen in a manner similar to that of alkali metals. (wikipedia.org)
  • nitrogen
  • this name is instead used in many languages, such as French, Russian, and Turkish, and appears in the English names of some nitrogen compounds such as hydrazine, azides and azo compounds. (wikipedia.org)
  • This causes difficulty for both organisms and industry in converting N2 into useful compounds, but at the same time means that burning, exploding, or decomposing nitrogen compounds to form nitrogen gas releases large amounts of often useful energy. (wikipedia.org)
  • Nitrogen compounds have a very long history, ammonium chloride having been known to Herodotus. (wikipedia.org)
  • sticken "to choke or suffocate") and still remains in English in the common names of many nitrogen compounds, such as hydrazine and compounds of the azide ion. (wikipedia.org)
  • Carbon compounds form the basis of all known life on Earth, and the carbon-nitrogen cycle provides some of the energy produced by the Sun and other stars. (wikipedia.org)
  • organisms
  • Fossil fuels, coal, petroleum, and natural gas, which are derived from ancient organisms, necessarily contain organosulfur compounds, the removal of which is a major focus of oil refineries. (wikipedia.org)
  • pigments
  • In 1974, the U.S. consumption of lead compounds, excluding pigments and gasoline additives, was 642 tons. (wikipedia.org)
  • While some resulting nitro compounds are shock- and thermally-sensitive explosives, a few are stable enough to be used in munitions and demolition, while others are still more stable and used as pigments in inks and dyes. (wikipedia.org)
  • stable
  • The first-ever isolation of a wide range of diamondoids from petroleum took place in the following steps: a vacuum distillation above 345 °C, the equivalent atmospheric boiling point, then pyrolysis at 400 to 450 °C in order to remove all non-diamondoid compounds (diamondoids are thermodynamically very stable and will survive this pyrolysis) and then a series of high-performance liquid chromatography separation techniques. (wikipedia.org)
  • ions
  • This theme relies on the study of the design and mechanism of action of metal-containing pharmaceuticals, and compounds that interact with endogenous metal ions in enzyme active sites. (wikipedia.org)
  • atoms
  • The compound crystallizes in the cubic system with the lead atoms in a face-centred cubic system. (wikipedia.org)
  • Introduction of halogen atoms into gold(III) tetraaza metallocomplexes. (wikipedia.org)
  • The covalent radius of fluorine of about 71 picometers found in F2 molecules is significantly larger than that in other compounds because of this weak bonding between the two fluorine atoms. (wikipedia.org)
  • group 11
  • Silver is similar in its physical and chemical properties to its two vertical neighbours in group 11 of the periodic table, copper and gold. (wikipedia.org)
  • chemical
  • Historically, the value of gold was rooted in its relative rarity, easy handling and minting, easy smelting and fabrication, resistance to corrosion and other chemical reactions (nobility) and its distinctive color. (wikipedia.org)
  • copper
  • Most silver is produced as a byproduct of copper, gold, lead, and zinc refining. (wikipedia.org)
  • Silver crystallizes in a face-centered cubic lattice with bulk coordination number 12, where only the single 5s electron is delocalized, similarly to copper and gold. (wikipedia.org)
  • Only in atomic physics is there a strict definition, which includes only copper, silver, and gold, because they have completely filled d-subshells. (wikipedia.org)
  • metal
  • A relative rare element, gold is a precious metal that has been used for coinage , jewelry , and other arts throughout recorded history . (wikipedia.org)
  • Gold has been known from prehistoric times and was possibly the first metal used by humans. (thefreedictionary.com)
  • Silver metal is used in many bullion coins, sometimes alongside gold: while it is more abundant than gold, it is much less abundant as a native metal. (wikipedia.org)
  • In addition to this term's function as a compound noun, there are circumstances where noble is used as an adjective for the noun metal. (wikipedia.org)
  • known
  • They are often associated with foul odors, but many of the sweetest compounds known are organosulfur derivatives, e.g., saccharin. (wikipedia.org)
  • platinum
  • Compounds containing platinum, such as cisplatin, oxaliplatin and carboplatin, are applied in chemotherapy against certain types of cancer. (wikipedia.org)
  • forms
  • Carbon forms a vast number of compounds, more than any other element, with almost ten million compounds described to date, and yet that number is but a fraction of the number of theoretically possible compounds under standard conditions. (wikipedia.org)
  • Although it forms an extraordinary variety of compounds, most forms of carbon are comparatively unreactive under normal conditions. (wikipedia.org)
  • Fluorine forms compounds with all elements except neon and helium. (wikipedia.org)