"Hippolyte-Victor Collet-Descotils Hippolyte-Victor Collet-Descotils (November 21, 1773 in Caen – December 6, 1815 in Paris) was a French chemist. He studied in the École des Mines de Paris, and was a student and friend of Louis Nicolas Vauquelin. He is best known for confirming the discovery of chromium by Vauquelin, and for independently discovering iridium in 1803. In 1806, Collet-Descotils misidentified erythronium, a new element discovered in Mexico by Andrés Manuel del Río, thinking that it was chromium. This resulted in Alexander von Humboldt rejecting Del Río's discovery. The same element was rediscovered thirty years later in Sweden and renamed"
"Vanadium Vanadium is a chemical element with symbol V and atomic number 23. It is a hard, silvery-grey, ductile, malleable transition metal. The elemental metal is rarely found in nature, but once isolated artificially, the formation of an oxide layer (passivation) somewhat stabilizes the free metal against further oxidation. Andrés Manuel del Río discovered compounds of vanadium in 1801 in Mexico by analyzing a new lead-bearing mineral he called ""brown lead"", and presumed its qualities were due to the presence of a new element, which he named ""erythronium"" (derived from Greek for ""red"") since, upon heating, most of the salts"
"a black powder, which he thought was the newly discovered metal itself (in fact, that powder was an oxide of uranium). He named the newly discovered element after the planet Uranus (named after the primordial Greek god of the sky), which had been discovered eight years earlier by William Herschel. In 1841, Eugène-Melchior Péligot, Professor of Analytical Chemistry at the Conservatoire National des Arts et Métiers (Central School of Arts and Manufactures) in Paris, isolated the first sample of uranium metal by heating uranium tetrachloride with potassium. Henri Becquerel discovered radioactivity by using uranium in 1896. Becquerel made the discovery"
"obtain enough for further experiments. In 1803, British scientist Smithson Tennant (1761–1815) analyzed the insoluble residue and concluded that it must contain a new metal. Vauquelin treated the powder alternately with alkali and acids and obtained a volatile new oxide, which he believed to be of this new metal—which he named ""ptene"", from the Greek word ""ptēnós"", ""winged"". Tennant, who had the advantage of a much greater amount of residue, continued his research and identified the two previously undiscovered elements in the black residue, iridium and osmium. He obtained dark red crystals (probably of ]·""n"") by a sequence of reactions"
"Chrome yellow Chrome yellow is lead(II) chromate (PbCrO). It occurs naturally as the mineral crocoite but the mineral itself was never used as a pigment for paint. After the French chemist Louis Vauquelin discovered the new element chromium in 1797 lead chromate was synthesized in the laboratory and its use as a pigment began in the second decade of the nineteenth century. Chrome yellow had been commonly produced by mixing solutions of lead nitrate and potassium chromate and filtering off the lead chromate precipitate. Because the pigment tends to react with hydrogen sulfide and darken on exposure to air over"
"can cause violent oxidation of organic material. Nitrogen Nitrogen is a chemical element with symbol N and atomic number 7. It was first discovered and isolated by Scottish physician Daniel Rutherford in 1772. Although Carl Wilhelm Scheele and Henry Cavendish had independently done so at about the same time, Rutherford is generally accorded the credit because his work was published first. The name ""nitrogène"" was suggested by French chemist Jean-Antoine-Claude Chaptal in 1790, when it was found that nitrogen was present in nitric acid and nitrates. Antoine Lavoisier suggested instead the name azote, from the Greek άζωτικός ""no life"", as"
"as vanadium. In 1815, a few months before his death, he got the position of director of École des Mines de Paris, in charge of transferring the school to a new building. He is buried in the 10th Division of the Père Lachaise Cemetery of Paris. Hippolyte-Victor Collet-Descotils Hippolyte-Victor Collet-Descotils (November 21, 1773 in Caen – December 6, 1815 in Paris) was a French chemist. He studied in the École des Mines de Paris, and was a student and friend of Louis Nicolas Vauquelin. He is best known for confirming the discovery of chromium by Vauquelin, and for independently discovering"
"corrosion. The solid vanadium compounds also abrade engine components. Vanadium Vanadium is a chemical element with symbol V and atomic number 23. It is a hard, silvery-grey, ductile, malleable transition metal. The elemental metal is rarely found in nature, but once isolated artificially, the formation of an oxide layer (passivation) somewhat stabilizes the free metal against further oxidation. Andrés Manuel del Río discovered compounds of vanadium in 1801 in Mexico by analyzing a new lead-bearing mineral he called ""brown lead"", and presumed its qualities were due to the presence of a new element, which he named ""erythronium"" (derived from Greek"
"the Greek word ""khalkόs"" (χαλκός) principally meaning copper (the term was also used for bronze/brass, any metal in the poetic sense, ore or coin), and the Latinised Greek word ""genēs"", meaning ""born"" or ""produced"". Sulfur has been known since antiquity, and oxygen was recognized as an element in the 18th century. Selenium, tellurium and polonium were discovered in the 19th century, and livermorium in 2000. All of the chalcogens have six valence electrons, leaving them two electrons short of a full outer shell. Their most common oxidation states are −2, +2, +4, and +6. They have relatively low atomic radii,"
"with French chemist Louis Vauquelin, the first to isolate the element chromium in 1797 created an intense malachite green glaze called viridian that was able to remain stable at very high temperatures. The firm's products were sold to the French upper class and to several courts of Europe, as well as one of the earliest state china services, used by President James Madison in the White House in or about 1814 (purchased privately on Madison's behalf in 1806 when he was Secretary of State, and used by him as President after the burning of the mansion and its contents by"
"a meeting of the Imperial Institute of France. On 6 December, Gay-Lussac announced that the new substance was either an element or a compound of oxygen. It was Gay-Lussac who suggested the name """"iode"""", from the Greek word (""ioeidēs"") for violet (because of the colour of iodine vapor). Ampère had given some of his sample to English chemist Humphry Davy (1778–1829), who experimented on the substance and noted its similarity to chlorine. Davy sent a letter dated 10 December to the Royal Society of London stating that he had identified a new element. Arguments erupted between Davy and Gay-Lussac over"
"Titanium Titanium is a chemical element with symbol Ti and atomic number 22. It is a lustrous transition metal with a silver color, low density, and high strength. Titanium is resistant to corrosion in sea water, aqua regia, and chlorine. Titanium was discovered in Cornwall, Great Britain, by William Gregor in 1791, and was named by Martin Heinrich Klaproth after the Titans of Greek mythology. The element occurs within a number of mineral deposits, principally rutile and ilmenite, which are widely distributed in the Earth's crust and lithosphere, and it is found in almost all living things, water bodies, rocks,"
"can regarded as a portmanteau of ""borax"" and ""carbon"". Aluminium was named by Humphry Davy in the early 1800s. It is derived from the Greek word ""alumen"", meaning bitter salt, or the Latin ""alum"", the mineral. Gallium is derived from the Latin ""Gallia"", referring to France, the place of its discovery. Indium comes from the Latin word ""indicum"", meaning indigo dye, and refers to the element's prominent indigo spectroscopic line. Thallium, like indium, is named after the Greek word for the color of its spectroscopic line: ""thallos"", meaning a green twig or shoot. ""Nihonium"" is named after Japan (""Nihon"" in"
"recent diamond jubilee. He assigned it the symbol Vc. By 1905, however, French chemist Georges Urbain had proven that victorium was not a distinct element but rather an impurity of gadolinium. Victorium Victorium, originally named monium, is a mixture of gadolinium and terbium. In 1898, English chemist William Crookes reported his discovery of it in his inaugural address as president of the British Association for the Advancement of Science. He identified the new substance, based on an analysis of the unique phosphorescence and other ultraviolet-visible spectral phenomena, as a new chemical element, although this was later shown to be false."
"Early analyses of emeralds and beryls by Martin Heinrich Klaproth, Torbern Olof Bergman, Franz Karl Achard, and Johann Jakob Bindheim always yielded similar elements, leading to the fallacious conclusion that both substances are aluminium silicates. Mineralogist René Just Haüy discovered that both crystals are geometrically identical, and he asked chemist Louis-Nicolas Vauquelin for a chemical analysis. In a 1798 paper read before the Institut de France, Vauquelin reported that he found a new ""earth"" by dissolving aluminium hydroxide from emerald and beryl in an additional alkali. The editors of the journal ""Annales de Chimie et de Physique"" named the new"
"colors with acidity. In 1702, German chemist Georg Stahl coined the name ""phlogiston"" for the substance believed to be released in the process of burning. Around 1735, Swedish chemist Georg Brandt analyzed a dark blue pigment found in copper ore. Brandt demonstrated that the pigment contained a new element, later named cobalt. In 1751, a Swedish chemist and pupil of Stahl's named Axel Fredrik Cronstedt, identified an impurity in copper ore as a separate metallic element, which he named nickel. Cronstedt is one of the founders of modern mineralogy. Cronstedt also discovered the mineral scheelite in 1751, which he named"
"meaning liquid silver; mercury is also known as quicksilver in English. The symbols for the other eight are also derived from descriptions of their properties in Latin. Systematic nomenclature began after Louis-Bernard Guyton de Morveau stated the need for “a constant method of denomination, which helps the intelligence and relieves the memory”. The resulting system was popularized by Antoine Lavoisier's publication of ""Méthode de nomenclature chimique"" (Method of Chemical Nomenclature) in 1787. Lavoisier proposed that elements be named after their properties. For the next 125 years, most chemists followed this suggestion, using Greek and Latin roots to compose the names;"
"Hafnium Hafnium is a chemical element with symbol Hf and atomic number 72. A lustrous, silvery gray, tetravalent transition metal, hafnium chemically resembles zirconium and is found in many zirconium minerals. Its existence was predicted by Dmitri Mendeleev in 1869, though it was not identified until 1923, by Coster and Hevesy, making it the last stable element to be discovered. Hafnium is named after ""Hafnia"", the Latin name for Copenhagen, where it was discovered. Hafnium is used in filaments and electrodes. Some semiconductor fabrication processes use its oxide for integrated circuits at 45 nm and smaller feature lengths. Some superalloys"
"Copernicium Copernicium is a synthetic chemical element with symbol Cn and atomic number 112. It is an extremely radioactive element, and can only be created in a laboratory. The most stable known isotope, copernicium-285, has a half-life of approximately 29 seconds. Copernicium was first created in 1996 by the GSI Helmholtz Centre for Heavy Ion Research near Darmstadt, Germany. It is named after the astronomer Nicolaus Copernicus. In the periodic table of the elements, copernicium is a d-block transactinide element and a group 12 element. During reactions with gold, it has been shown to be an extremely volatile metal, so"
"Nitrogen Nitrogen is a chemical element with symbol N and atomic number 7. It was first discovered and isolated by Scottish physician Daniel Rutherford in 1772. Although Carl Wilhelm Scheele and Henry Cavendish had independently done so at about the same time, Rutherford is generally accorded the credit because his work was published first. The name ""nitrogène"" was suggested by French chemist Jean-Antoine-Claude Chaptal in 1790, when it was found that nitrogen was present in nitric acid and nitrates. Antoine Lavoisier suggested instead the name azote, from the Greek άζωτικός ""no life"", as it is an asphyxiant gas; this name"
"Selenium Selenium is a chemical element with symbol Se and atomic number 34. It is a nonmetal (more rarely considered a metalloid) with properties that are intermediate between the elements above and below in the periodic table, sulfur and tellurium, and also has similarities to arsenic. It rarely occurs in its elemental state or as pure ore compounds in the Earth's crust. Selenium (from Ancient Greek (selḗnē) ""Moon"") was discovered in 1817 by Jöns Jacob Berzelius, who noted the similarity of the new element to the previously discovered tellurium (named for the Earth). Selenium is found in , where it"
"northern Europe, thanks to the 17th century invention of the heated greenhouse, a building type which became known as an orangerie. The French artist Jean-Honoré Fragonard depicted an allegorical figure of ""inspiration"" dressed in orange. In 1797 a French scientist Louis Vauquelin discovered the mineral crocoite, or lead chromate, which led in 1809 to the invention of the synthetic pigment chrome orange. Other synthetic pigments, cobalt red, cobalt yellow, and cobalt orange, the last made from cadmium sulfide plus cadmium selenide, soon followed. These new pigments, plus the invention of the metal paint tube in 1841, made it possible for"
"""selenium"", after the moon. Silicon: In 1823, Berzelius prepared amorphous silicon by reducing potassium fluorosilicate with molten potassium metal. Bromine: Balard and Gmelin both discovered bromine in the autumn of 1825 and published their results in the following year. Helium: In 1868, Janssen and Lockyer independently observed a yellow line in the solar spectrum that did not match that of any other element. In 1895, in each case at around the same time, Ramsay, Cleve, and Langlet independently observed helium trapped in cleveite. Fluorine: André-Marie Ampère predicted an element analogous to chlorine obtainable from hydrofluoric acid, and between 1812 and"
"Molybdenum Molybdenum is a chemical element with symbol Mo and atomic number 42. The name is from Neo-Latin ""molybdaenum"", from Ancient Greek "", meaning lead, since its ores were confused with lead ores. Molybdenum minerals have been known throughout history, but the element was discovered (in the sense of differentiating it as a new entity from the mineral salts of other metals) in 1778 by Carl Wilhelm Scheele. The metal was first isolated in 1781 by Peter Jacob Hjelm. Molybdenum does not occur naturally as a free metal on Earth; it is found only in various oxidation states in minerals."
"a metal in a platinum residue they called ‘""ptène""’. In 1803, Smithson Tennant analyzed the insoluble residue and concluded that it must contain a new metal. Vauquelin treated the powder alternately with alkali and acids and obtained a volatile new oxide, which he believed was of this new metal—which he named ""ptene"", from the Greek word (ptènos) for winged. However, Tennant, who had the advantage of a much larger amount of residue, continued his research and identified two previously undiscovered elements in the black residue, iridium and osmium. He obtained a yellow solution (probably of ""cis""–<nowiki>[</nowiki>Os(OH)O<nowiki>]</nowiki>) by reactions with sodium"
"in 1900. At right is displayed the web color medium turquoise. At right is displayed the web color dark turquoise. Turquoise (color) Turquoise () is a blue/green color, based on the gem of the same name. The word ""turquoise"" comes from the French for ""Turkish"", as the gem was originally imported from Turkey. The first recorded use of ""turquoise"" as a color name in English was in 1573. The X11 color named turquoise is displayed on the right. Turquoise is an opaque, blue-to-green mineral that is a hydrous phosphate of copper and aluminium, with the chemical formula CuAl(PO)(OH)·4HO. It is"
"elements of the 7th period. Francium is a chemical element with symbol Fr and atomic number 87. It was formerly known as eka-caesium and actinium K. It is one of the two least electronegative elements, the other being caesium. Francium is a highly radioactive metal that decays into astatine, radium, and radon. As an alkali metal, it has one valence electron. Francium was discovered by Marguerite Perey in France (from which the element takes its name) in 1939. It was the last element discovered in nature, rather than by synthesis. Outside the laboratory, francium is extremely rare, with trace amounts"
"Ausonium Ausonium (atomic symbol Ao) was the name assigned to the element with atomic number 93, now known as neptunium. It was named after a Greek name of Italy, Ausonia. The same team assigned the name hesperium to element 94, after Hesperia, a poetic name of Italy. (Element 94 was later named plutonium). The discovery of the element, now discredited, was made by Enrico Fermi and a team of scientists at the University of Rome in 1934. In the same year Ida Noddack had already presented alternative explanations for the experimental results of Fermi. Following the discovery of nuclear fission"
"forms as an active center of enzymes, such as the vanadium bromoperoxidase of some ocean algae. Vanadium was discovered by Andrés Manuel del Río, a Spanish-Mexican mineralogist, in 1801. Del Río extracted the element from a sample of Mexican ""brown lead"" ore, later named vanadinite. He found that its salts exhibit a wide variety of colors, and as a result he named the element ""panchromium"" (Greek: παγχρώμιο ""all colors""). Later, Del Río renamed the element ""erythronium"" (Greek: ερυθρός ""red"") because most of the salts turned red upon heating. In 1805, the French chemist Hippolyte Victor Collet-Descotils, backed by del Río's"
"Iodine Iodine is a chemical element with symbol I and atomic number 53. The heaviest of the stable halogens, it exists as a lustrous, purple-black non-metallic solid at standard conditions that sublimes readily to form a violet gas. The elemental form was discovered by the French chemist Bernard Courtois in 1811. It was named two years later by Joseph Louis Gay-Lussac from this property, after the Greek ""ἰώδης"" ""violet-coloured"". Iodine occurs in many oxidation states, including iodide (I), iodate (), and the various periodate anions. It is the least abundant of the stable halogens, being the sixty-first most abundant element."
"Neon Neon is a chemical element with symbol Ne and atomic number 10. It is a noble gas. Neon is a colorless, odorless, inert monatomic gas under standard conditions, with about two-thirds the density of air. It was discovered (along with krypton and xenon) in 1898 as one of the three residual rare inert elements remaining in dry air, after nitrogen, oxygen, argon and carbon dioxide were removed. Neon was the second of these three rare gases to be discovered and was immediately recognized as a new element from its bright red emission spectrum. The name neon is derived from"
"mg/m over an 8-hour workday. The National Institute for Occupational Safety and Health (NIOSH) has set the same recommended exposure limit (REL). At levels of 50 mg/m, hafnium is immediately dangerous to life and health. Hafnium Hafnium is a chemical element with symbol Hf and atomic number 72. A lustrous, silvery gray, tetravalent transition metal, hafnium chemically resembles zirconium and is found in many zirconium minerals. Its existence was predicted by Dmitri Mendeleev in 1869, though it was not identified until 1923, by Coster and Hevesy, making it the last stable element to be discovered. Hafnium is named after ""Hafnia"","
"Palladium Palladium is a chemical element with symbol Pd and atomic number 46. It is a rare and lustrous silvery-white metal discovered in 1803 by William Hyde Wollaston. He named it after the asteroid Pallas, which was itself named after the epithet of the Greek goddess Athena, acquired by her when she slew Pallas. Palladium, platinum, rhodium, ruthenium, iridium and osmium form a group of elements referred to as the platinum group metals (PGMs). These have similar chemical properties, but palladium has the lowest melting point and is the least dense of them. More than half the supply of palladium"