"in 1810, who named it chlorine, from the Greek word χλωρος (chlōros), meaning ""green-yellow."" Chlorine is a component of various compounds, including table salt. It is the second most abundant halogen and 21st most abundant chemical element in Earth's crust. The great oxidizing potential of chlorine led it to its bleaching and disinfectant uses, as well as uses of an essential reagent in the chemical industry. As a common disinfectant, chlorine compounds are used in swimming pools to keep them clean and sanitary. In the upper atmosphere, chlorine-containing molecules such as chlorofluorocarbons have been implicated in ozone depletion. ""Argon"" (symbol"
"Chlorine Chlorine is a chemical element with symbol Cl and atomic number 17. The second-lightest of the halogens, it appears between fluorine and bromine in the periodic table and its properties are mostly intermediate between them. Chlorine is a yellow-green gas at room temperature. It is an extremely reactive element and a strong oxidising agent: among the elements, it has the highest electron affinity and the third-highest electronegativity, behind only oxygen and fluorine. The most common compound of chlorine, sodium chloride (common salt), has been known since ancient times. Around 1630, chlorine gas was first synthesised in a chemical reaction,"
"the mineral fluorospar, which was used as a flux in metal working. Chlorine's name comes from the Greek word ""chloros"", meaning ""greenish-yellow"". Bromine's name comes from the Greek word ""bromos"", meaning ""stench"". Iodine's name comes from the Greek word ""iodes"", meaning ""violet"". Astatine's name comes from the Greek word ""astatos"", meaning ""unstable"". Tennessine is named after the US state of Tennessee. The halogens show trends in chemical bond energy moving from top to bottom of the periodic table column with fluorine deviating slightly. (It follows trend in having the highest bond energy in compounds with other atoms, but it has"
"17 in the periodic table, below the five halogens; fluorine, chlorine, bromine, iodine, and astatine, each of which has seven valence electrons with a configuration of . For tennessine, being in the seventh period (row) of the periodic table, continuing the trend would predict a valence electron configuration of , and it would therefore be expected to behave similarly to the halogens in many respects that relate to this electronic state. However, going down group 17, the metallicity of the elements increases; for example, iodine already exhibits a metallic luster in the solid state, and astatine is often classified as"
"Halogen The halogens () are a group in the periodic table consisting of five chemically related elements: fluorine (F), chlorine (Cl), bromine (Br), iodine (I), and astatine (At). The artificially created element 117 (tennessine, Ts) may also be a halogen. In the modern IUPAC nomenclature, this group is known as group 17. The symbol X is often used generically to refer to any halogen. The name ""halogen"" means ""salt-producing"". When halogens react with metals they produce a wide range of salts, including calcium fluoride, sodium chloride (common table salt), silver bromide and potassium iodide. The group of halogens is the"
"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"
"fats, and aromatic esters, carotenoids and terpenes. With nitrogen it forms alkaloids, and with the addition of sulfur also it forms antibiotics, amino acids, and rubber products. With the addition of phosphorus to these other elements, it forms DNA and RNA, the chemical-code carriers of life, and adenosine triphosphate (ATP), the most important energy-transfer molecule in all living cells. Nitrogen is the chemical element with atomic number 7, the symbol N and atomic mass 14.00674 u. Elemental nitrogen is a colorless, odorless, tasteless and mostly inert diatomic gas at standard conditions, constituting 78.08% by volume of Earth's atmosphere. The element"
"factories, coal-burning power plants, and metal sewers. The main source of elevated thallium concentrations in water is the leaching of thallium from ore processing operations. Thallium Thallium is a chemical element with symbol Tl and atomic number 81. It is a gray post-transition metal that is not found free in nature. When isolated, thallium resembles tin, but discolors when exposed to air. Chemists William Crookes and Claude-Auguste Lamy discovered thallium independently in 1861, in residues of sulfuric acid production. Both used the newly developed method of flame spectroscopy, in which thallium produces a notable green spectral line. Thallium, from Greek"
"Oxygen-17 Oxygen-17 is a low-abundant, natural, stable isotope of oxygen (0.0373% in seawater; approximately twice as abundant as deuterium). As the only stable isotope of oxygen possessing a nuclear spin (+5/2) and a favorable characteristic of field-independent relaxation in liquid water, O-17 enables NMR studies of oxidative metabolic pathways through compounds containing O (i.e. metabolically produced HO water by oxidative phosphorylation in mitochondria) at high magnetic fields. Water used as nuclear reactor coolant is subjected to intense neutron flux. Natural water starts out with 373 ppm of O-17; heavy water starts out incidentally enriched to about 550 ppm of oxygen-17."
"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"
"for example, hydrogen (""water-producing""), oxygen (""acid-producing""), nitrogen (""soda-producing""), bromine (""stink""), and argon (""no reaction"") were based on Greek roots, while the names of iodine and chlorine were derived from the Greek words for their characteristic colors. Indium, rubidium, and thallium were similarly named for the colors of particular lines in their emission spectra. Iridium, which forms compounds of many different colors, takes its name from ""iris"", the Latin for ""rainbow"". The noble gases have all been named for their origin or properties. Helium comes from the Greek ""helios"", meaning ""sun"" because it was first detected as a line in the"
"Chromium Chromium is a chemical element with symbol Cr and atomic number 24. It is the first element in group 6. It is a steely-grey, lustrous, hard and brittle transition metal. Chromium boasts a high usage rate as a metal that is able to be highly polished while resisting tarnishing. Chromium is also the main component of stainless steel, a popular steel alloy due to its uncommonly high specular reflection. Simple polished chromium reflects almost 70% of the visible spectrum, with almost 90% of infrared light waves being reflected. The name of the element is derived from the Greek word"
"Chlorine-37 Chlorine-37 (Cl), is one of the stable isotopes of chlorine, the other being chlorine-35 (). Its nucleus contains 17 protons and 20 neutrons for a total of 37 nucleons. Chlorine-37 accounts for 24.23% of natural chlorine, chlorine-35 accounting for 75.77%, giving chlorine atoms in bulk an apparent atomic weight of . Remarkably, solar neutrinos were discovered by an experiment using a radiochemical method based on chlorine-37 transmutation. One of the historically important radiochemical methods of solar neutrino detection is based on inverse electron capture triggered by the absorption of an electron neutrino. Chlorine-37 transmutes into argon-37 via the reaction"
"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"
"Many scientists in the field called it ""element 117"", with the symbol ""E117"", ""(117)"", or ""117"". According to guidelines of IUPAC valid at the moment of the discovery approval, the permanent names of new elements should have ended in ""-ium""; this included element 117, even if the element was a halogen, which traditionally have names ending in ""-ine""; however, the new recommendations published in 2016 recommended using the ""-ine"" ending for all new group 17 elements. The IUPAC guidelines specify that the discovery team has naming rights for the element. After the original synthesis in 2010, Dawn Shaughnessy of LLNL"
"Brown in 1906. It means in Greek ""wax birth"" (Greek: κηρός ""wax"" and -gen, γένεση ""birth""). Kerogen is a mixture of organic chemical compounds that make up a portion of the organic matter in sedimentary rocks. As kerogen is a mixture of organic material, rather than a specific chemical, it cannot be given a chemical formula. Its chemical composition can vary distinctively from sample to sample. For example, kerogen from the Green River Formation oil shale deposit of western North America contains elements in the proportions carbon 215 : hydrogen 330 : oxygen 12 : nitrogen 5 : sulfur 1."
"This work, titled ""Méthode de nomenclature chimique"" (""Method of Chemical Nomenclature"", 1787), introduced a new system which was tied inextricably to Lavoisier's new oxygen theory of chemistry. The Classical elements of earth, air, fire, and water were discarded, and instead some 55 substances which could not be decomposed into simpler substances by any known chemical means were provisionally listed as elements. The elements included light; caloric (matter of heat); the principles of oxygen, hydrogen, and azote (nitrogen); carbon; sulfur; phosphorus; the yet unknown ""radicals"" of muriatic acid (hydrochloric acid), boric acid, and ""fluoric"" acid; 17 metals; 5 earths (mainly oxides"
"the Latin word for green, so using the word ""viridian"" sounds more elegant than simply referring to the Old English word ""green"". Viridian Viridian is a blue-green pigment, a hydrated chromium(III) oxide, of medium saturation and relatively dark in value. It is composed more of green than blue. Specifically, it is a dark shade of spring green, so it is the color between green and teal on the color wheel, or, in paint, a tertiary blue–green color. Viridian takes its name from the Latin ""viridis"", meaning ""green"". The first recorded use of ""viridian"" as a color name in English was"
"grew until the part failed. The fracture surface shows iron and calcium salts that were deposited in the leaking joint from the water supply before failure. The element iron can combine with chlorine at high temperatures in a strong exothermic reaction, creating a ""chlorine-iron fire"". Chlorine-iron fires are a risk in chemical process plants, where much of the pipework that carries chlorine gas is made of steel. Chlorine Chlorine is a chemical element with symbol Cl and atomic number 17. The second-lightest of the halogens, it appears between fluorine and bromine in the periodic table and its properties are mostly"
"Pnictogen A pnictogen is one of the chemical elements in group 15 of the periodic table. This group is also known as the nitrogen family. It consists of the elements nitrogen (N), phosphorus (P), arsenic (As), antimony (Sb), bismuth (Bi), and perhaps the chemically uncharacterized synthetic element moscovium (Mc). In modern IUPAC notation, it is called Group 15. In CAS and the old IUPAC systems it was called Group V and Group V respectively (pronounced ""group five A"" and ""group five B"", ""V"" for the Roman numeral 5). In the field of semiconductor physics, it is still usually called Group"
"Bromine Bromine is a chemical element with symbol Br and atomic number 35. It is the third-lightest halogen, and is a fuming red-brown liquid at room temperature that evaporates readily to form a similarly coloured gas. Its properties are thus intermediate between those of chlorine and iodine. Isolated independently by two chemists, Carl Jacob Löwig (in 1825) and Antoine Jérôme Balard (in 1826), its name was derived from the Ancient Greek βρῶμος (""stench""), referencing its sharp and disagreeable smell. Elemental bromine is very reactive and thus does not occur free in nature, but in colourless soluble crystalline mineral halide salts,"
"Thallium Thallium is a chemical element with symbol Tl and atomic number 81. It is a gray post-transition metal that is not found free in nature. When isolated, thallium resembles tin, but discolors when exposed to air. Chemists William Crookes and Claude-Auguste Lamy discovered thallium independently in 1861, in residues of sulfuric acid production. Both used the newly developed method of flame spectroscopy, in which thallium produces a notable green spectral line. Thallium, from Greek , , meaning ""a green shoot or twig"", was named by Crookes. It was isolated by both Lamy and Crookes in 1862; Lamy by electrolysis,"
"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"
"Chrysene Chrysene is a polycyclic aromatic hydrocarbon (PAH) with the molecular formula that consists of four fused benzene rings. It is a natural constituent of coal tar, from which it was first isolated and characterized. It is also found in creosote at levels of 0.5-6 mg/kg. The name ""chrysene"" originates from Greek ""Χρύσoς"" (""chrysos""), meaning ""gold"", and is due to the golden-yellow color of the crystals of the hydrocarbon, thought to be the proper color of the compound at the time of its isolation and characterization. However, high purity chrysene is colorless, the yellow hue being due to the traces"
"green food colorings which has been approved by the US Food and Drug Administration. Chlorophyll, the E numbers E140 and E141, is the most common green chemical found in nature, and only allowed in certain medicines and cosmetic materials. Quinoline Yellow (E104) is a commonly used coloring in the United Kingdom but is banned in Australia, Japan, Norway and the United States. Green S (E142) is prohibited in many countries, for it is known to cause hyperactivity, asthma, urticaria, and insomnia. To create green sparks, fireworks use barium salts, such as barium chlorate, barium nitrate crystals, or barium chloride, also"
"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"
"Germanium Germanium is a chemical element with symbol Ge and atomic number 32. It is a lustrous, hard, grayish-white metalloid in the carbon group, chemically similar to its group neighbors tin and silicon. Pure germanium is a semiconductor with an appearance similar to elemental silicon. Like silicon, germanium naturally reacts and forms complexes with oxygen in nature. Because it seldom appears in high concentration, germanium was discovered comparatively late in the history of chemistry. Germanium ranks near fiftieth in relative abundance of the elements in the Earth's crust. In 1869, Dmitri Mendeleev predicted its existence and some of its properties"
"Chlorophyll Chlorophyll (also chlorophyl) is any of several related green pigments found in cyanobacteria and the chloroplasts of algae and plants. Its name is derived from the Greek words , (""green"") and , (""leaf""). Chlorophyll is essential in photosynthesis, allowing plants to absorb energy from light. Chlorophylls absorb light most strongly in the blue portion of the electromagnetic spectrum as well as the red portion. Conversely, it is a poor absorber of green and near-green portions of the spectrum, which it reflects, producing the green color of chlorophyll-containing tissues. Two types of chlorophyll exist in the photosystems of green plants:"
"and zinc were also used to create green paints as early as the 18th century. Cobalt green, sometimes known as Rinman's green or zinc green, is a translucent green pigment made by heating a mixture of cobalt (II) oxide and zinc oxide. Sven Rinman, a Swedish chemist, discovered this compound in 1780. Green chrome oxide was a new synthetic green created by a chemist named Pannetier in Paris in about 1835. Emerald green was a synthetic deep green made in the 19th century by hydrating chrome oxide. It was also known as Guignet green. There is no natural source for"
"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"
"Manganese Manganese is a chemical element with symbol Mn and atomic number 25. It is not found as a free element in nature; it is often found in minerals in combination with iron. Manganese is a metal with important industrial metal alloy uses, particularly in stainless steels. Historically, manganese is named for pyrolusite and other black minerals from the region of Magnesia in Greece, which also gave its name to magnesium and the iron ore magnetite. By the mid-18th century, Swedish-German chemist Carl Wilhelm Scheele had used pyrolusite to produce chlorine. Scheele and others were aware that pyrolusite (now known"
"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."
"characteristic odor to rotting eggs and other biological processes. ""Chlorine"" (symbol Cl) is the second lightest halogen, found in the periodic table in group 17. The element forms diatomic molecules under standard conditions, called dichlorine. It has the highest electron affinity and the third highest electronegativity of all the elements; for this reason, chlorine is a strong oxidizing agent. The most common compound of chlorine, sodium chloride, has been known since ancient times; however, around 1630, chlorine gas was obtained by the Belgian chemist and physician Jan Baptist van Helmont. The synthesis and characterization of elemental chlorine occurred in 1774"