"of elements it sets on fire is diverse, containing hydrogen, potassium, phosphorus, arsenic, antimony, sulfur, selenium, tellurium, bromine, iodine, and powdered molybdenum, tungsten, rhodium, iridium, and iron. An impermeable fluoride layer is formed by sodium, magnesium, aluminium, zinc, tin, and silver, which may be removed by heating. When heated, even such noble metals as palladium, platinum, and gold are attacked and even the noble gases xenon and radon do not escape fluorination. Nickel containers are usually used due to that metal's great resistance to attack by chlorine trifluoride, stemming from the formation of an unreactive nickel fluoride layer. Its reaction"
"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"
"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"
"very penetrating, choking, and unpleasant odour. All four stable halogens experience intermolecular van der Waals forces of attraction, and their strength increases together with number of electrons among all homonuclear diatomic halogen molecules. Thus, the melting and boiling points of bromine are intermediate between those of chlorine and iodine. As a result of the increasing molecular weight of the halogens down the group, the density and heats of fusion and vaporisation of bromine are again intermediate between those of chlorine and iodine, although all their heats of vaporisation are fairly low (leading to high volatility) thanks to their diatomic molecular"
"Fluorene Fluorene , or 9""H""-fluorene, is a polycyclic aromatic hydrocarbon. It forms white crystals that exhibit a characteristic, aromatic odor similar to that of naphthalene. It is combustible. It has a violet fluorescence, hence its name. For commercial purposes it is obtained from coal tar. It is insoluble in water and soluble in many organic solvents. Although fluorene is obtained from coal tar, it can also be prepared by dehydrogenation of diphenylmethane. Alternatively, it can be prepared by the reduction of fluorenone with zinc. The fluorene molecule is nearly planar, although each of the two benzene rings is coplanar with"
"only xenon and krypton react, and only under special conditions. At room temperature, fluorine is a gas of diatomic molecules, pale yellow when pure (sometimes described as yellow-green). It has a characteristic pungent odor detectable at 20 ppb. Fluorine condenses into a bright yellow liquid at −188 °C (−306 °F), a transition temperature similar to those of oxygen and nitrogen. Fluorine has two solid forms, α- and β-fluorine. The latter crystallizes at −220 °C (−364 °F) and is transparent and soft, with the same disordered cubic structure of freshly crystallized solid oxygen, unlike the orthorhombic systems of other solid halogens."
"and to physicist André-Marie Ampère. On December 6, 1813, 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 ιώδες (iodes) for violet (because of the color of iodine vapor). Ampère had given some of his sample to Humphry Davy. Davy did some experiments on the substance and noted its similarity to chlorine. Davy sent a letter dated December 10 to the Royal Society of London stating that he had identified a new element. Arguments erupted between Davy and Gay-Lussac over who identified"
"a shiny black crystalline solid that melts at 114 °C and boils at 183 °C to form a violet gas. This trend occurs because the wavelengths of visible light absorbed by the halogens increase down the group (though astatine may not conform to it, depending on how metallic it turns out to be). Specifically, the violet colour of iodine gas results from the electron transition between the highest occupied antibonding ""π"" molecular orbital and the lowest vacant antibonding ""σ"" molecular orbital. Elemental iodine is slightly soluble in water, with one gram dissolving in 3450 ml at 20 °C and 1280"
"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,"
"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,"
"is a powerful oxidising agent (F + 2""e"" → 2HF = 2.87 V at pH 0); ""even water, in the form of steam, will catch fire in an atmosphere of fluorine"". Metal fluorides are generally ionic in nature. Chlorine is an irritating green-yellow diatomic gas that is extremely reactive, and has a gaseous density of 3.2 × 10 g/cm (about 2.5 times heavier than air). It condenses at −34.04 °C to an amber-coloured liquid and freezes at −101.5 °C into a yellow crystalline solid. The solid form (density 1.9 g/cm) has an orthorhombic crystalline structure and is soft and easily"
"Osmium tetroxide Osmium tetroxide (also osmium(VIII) oxide) is the chemical compound with the formula OsO. The compound is noteworthy for its many uses, despite its toxicity and the rarity of osmium. It also has a number of interesting properties, one being that the solid is volatile. The compound is colourless, but most samples appear yellow. This is most likely due to the presence of the impurity OsO, which is yellow-brown in colour. Osmium(VIII) oxide forms monoclinic crystals. It has a characteristic acrid chlorine-like odor. The element name osmium is derived from ""osme"", Greek for ""odor"". OsO is volatile: it sublimes"
"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"
"orange (""Citrus x aurantium""), rose (""Rosa"") and hyacinth (""Hyacinthus""). Heptanal is a flammable, slightly volatile colorless liquid of pervasive fruity to oily-greasy odor, which is miscible with alcohols and practically insoluble in water. Because of its sensitivity to oxidation, heptanal is filled under nitrogen and stabilized with 100 ppm hydroquinone. Heptanal forms flammable vapor-air mixtures. The compound has a flash point of 39.5 °C. The explosion range is between 1.1% by volume as the lower explosion limit (LEL) and 5.2% by volume as the upper explosion limit. Its ignition temperature is 205 °C. Heptanal can be used for the production"
"heated, giving off a yellow gas, which contains chlorine, oxygen and chlorine dioxide. A green solid is left that is a basic copper salt. Sulfur is highly reactive with copper chlorate, and it is important not to cross contaminate these chemicals, for example in pyrotechnic making. François-Marie Chertier used tetrammine copper chlorate to colour flames blue in 1843. This material was abbreviated TACC with formula Cu(NH)(ClO). TACC explodes on impact. The substance became known as Chertier'c copper for use in blue coloured pyrotechnics. However its deliquescence causes a problem. Mixtures with other metal salts can yield violet or lilac colours"
"strong oxidizing element causing the hydrogen to split from water in moist tissue, resulting in nascent oxygen and hydrogen chloride that cause corrosive tissue damage. Additionally oxidation of chlorine may form hypochlorous acid, which can penetrate cells and react with cytoplasmic proteins destroying cell structure. Chlorine’s odor provides early warning signs of exposure but causes olfactory fatigue or adaptations, reducing awareness of exposure at low concentrations. With increased exposure, symptoms may progress to labored respirations, severe coughing, chest tightness, wheezing, dyspnea, and broncospasm associated with a decrease in oxygen saturation level. . Severe exposure may result in changes in upper"
"state. Common indicators are cobalt(II) chloride and methyl violet. Cobalt (II) chloride is deep blue when dry and pink when wet, but it is toxic and carcinogenic, and was reclassified by the European Union in July 2000 as a toxic material. Methyl violet can be formulated to change from orange to green, or orange to colorless. It is also toxic and potentially carcinogenic, but is safe enough to have medicinal uses. Silica gel is non-toxic, non-flammable, and non-reactive and stable with ordinary usage. It will react with hydrogen fluoride, fluorine, oxygen difluoride, chlorine trifluoride, strong acids, strong bases, and oxidizers."
"calculations have been cited to propose that contributions from d orbitals in the shell below the valence shell are responsible. Another proposal is that polarization of the electron core of the strontium atom creates an approximately tetrahedral distribution of charge that interacts with the Sr−F bonds. It is almost insoluble in water (its K value is approximately 2.0x10 at 25 degrees Celsius). It irritates eyes and skin, and is harmful when inhaled or ingested. Similar to CaF and BaF, SrF displays superionic conductivity at elevated temperatures.<ref name=""http://www.newmet.co.uk/Products/koch/strontium.php"">https://web.archive.org/web/20051214052733/http://www.newmet.co.uk/Products/koch/strontium.php</ref> Strontium fluoride is transparent to light in the wavelengths from vacuum ultraviolet (150"
"vigorous fluorinating agent, although chlorine trifluoride is still more violent. Bromine pentafluoride explodes on reaction with water and fluorinates silicates at 450 °C. Although dibromine is a strong oxidising agent with a high first ionisation energy, very strong oxidisers such as peroxydisulfuryl fluoride (SOF) can oxidise it to form the cherry-red cation. A few other bromine cations are known, namely the brown and dark brown . The tribromide anion, , has also been characterised; it is analogous to triiodide. Bromine oxides are not as well-characterised as chlorine oxides or iodine oxides, as they are all fairly unstable: it was once"
"crushed. Chlorine is an insulator in all of its forms. It has a high ionisation energy (1251.2 kJ/mol), high electron affinity (349 kJ/mol; higher than fluorine), and high electronegativity (3.16). Chlorine is a strong oxidising agent (Cl + 2""e"" → 2HCl = 1.36 V at pH 0). Metal chlorides are largely ionic in nature. The common oxide of chlorine (ClO) is strongly acidic. Bromine is a deep brown diatomic liquid that is quite reactive, and has a liquid density of 3.1028 g/cm. It boils at 58.8 °C and solidifies at −7.3 °C to an orange crystalline solid (density 4.05 g/cm)."
"has received numerous reports of nausea, diarrhea, severe vomiting, and life-threatening low blood pressure caused by dehydration. Chlorine dioxide Chlorine dioxide is a chemical compound with the formula ClO. This yellowish-green gas crystallizes as bright orange crystals at −59 °C. As one of several oxides of chlorine, it is a potent and useful oxidizing agent used in water treatment and in bleaching. Chlorine dioxide is a neutral chlorine compound. It is very different from elemental chlorine, both in its chemical structure and in its behavior. One of the most important qualities of chlorine dioxide is its high water solubility, especially"
"producing ozone (whose characteristic smell, originally mistaken for a hypothetical substance called antozone, is responsible for the mineral's name) and hydrogen fluoride. Antozonite Antozonite (historically known as Stinkspat, Stinkfluss, Stinkstein, Stinkspar and fetid fluorite) is a radioactive fluorite variety first found in Wölsendorf, Bavaria, in 1841, and named in 1862. It is characterized by the presence of multiple inclusions containing elemental fluorine; when the crystals are crushed or broken, the elemental fluorine is released. It was postulated that beta radiation given by uranium inclusions continuously break down calcium fluoride into calcium and fluorine atoms. Fluorine atoms combine to produce difluoride"
"(turning it yellow or brown over time). Lanthanum oxide has replaced thorium dioxide in almost all modern high-index glasses. Thorium dioxide Thorium dioxide (ThO), also called thorium(IV) oxide, is a crystalline solid, often white or yellow in color. Also known as thoria, it is produced mainly as a by-product of lanthanide and uranium production. Thorianite is the name of the mineralogical form of thorium dioxide. It is moderately rare and crystallizes in an isometric system. The melting point of thorium oxide is 3300 °C – the highest of all known oxides. Only a few elements (including tungsten and carbon) and"
"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"
"Fluorine Fluorine is a chemical element with symbol F and atomic number 9. It is the lightest halogen and exists as a highly toxic pale yellow diatomic gas at standard conditions. As the most electronegative element, it is extremely reactive, as it reacts with almost all other elements, except for helium and neon. Among the elements, fluorine ranks 24th in universal abundance and 13th in terrestrial abundance. Fluorite, the primary mineral source of fluorine which gave the element its name, was first described in 1529; as it was added to metal ores to lower their melting points for smelting, the"
"Chlorophane Chlorophane, also sometimes known as pyroemerald, cobra stone, and pyrosmaragd, is a rare variety of the mineral fluorite with the unusual combined properties of thermoluminescence, thermophosphoresence, triboluminescence, and fluorescence: it will emit light in the visible spectrum when exposed to ultraviolet light, when heated, and when rubbed; if heated, it will continue to emit light for a period of time after a heat source is withdrawn. The small amount of heat generated by being held in the hand has been reported as enough to induce luminiscence, though this may be the result of experimental error. Although chemically very similar"
"a violet color. Mineral associations based on some physical properties include, but not limited to, halite, anhydrite, dolomite, gypsum, kainite, kieserite, polyhalite, and sylvite. Carnallite is found in saline marine deposits. Carnallite minerals are mineral sediments known as evaporites. Evaporites are concentrated by evaporation of seawater. The inflow of water must be below the evaporation or use levels. This creates a prolonged evaporation period. In controlled environment experiments, the halides form when 10%–20% of the original sample of water remains. Closer to 10 percent sylvite followed by Carnallite form. Carnallite is mostly used in fertilizers. It is an important source"
"chloride is also a dangerous chemical. Breathing in gas with more than fifty parts per million of hydrogen chloride can cause death in humans. Hydrogen bromide is even more toxic and irritating than hydrogen chloride. Breathing in gas with more than thirty parts per million of hydrogen bromide can be lethal to humans. Hydrogen iodide, like other hydrogen halides, is toxic. All the halogens are known to react with sodium to form sodium fluoride, sodium chloride, sodium bromide, sodium iodide, and sodium astatide. Heated sodium's reaction with halogens produces bright-orange flames. Sodium's reaction with chlorine is in the form of:"
"Thorium dioxide Thorium dioxide (ThO), also called thorium(IV) oxide, is a crystalline solid, often white or yellow in color. Also known as thoria, it is produced mainly as a by-product of lanthanide and uranium production. Thorianite is the name of the mineralogical form of thorium dioxide. It is moderately rare and crystallizes in an isometric system. The melting point of thorium oxide is 3300 °C – the highest of all known oxides. Only a few elements (including tungsten and carbon) and a few compounds (including tantalum carbide) have higher melting points. All thorium compounds are radioactive because there are no"
"Uranyl chloride Uranyl chloride, UOCl is an unstable, bright yellow coloured chemical compound of uranium. It forms large sand-like crystals which are highly soluble in water, alcohols, and ethers. Uranyl chloride and its two hydrates, UOCl·HO and UOCl·3HO, decompose in the presence of light, a fact discovered by Adolph Gehlen in 1804. This photosensitivity periodically attracted scientific curiosity and various unsuccessful attempts to develop photographic applications using the salts. As with most other uranic species this compound also exhibits fluorescence. Uranyl chloride forms when chlorine gas is passed over uranium dioxide at a red heat. However it is more usually"
"Conhydrine Conhydrine is a poisonous alkaloid found in poison hemlock (""Conium maculatum"") in small quantities. This oxygenated alkaloid was isolated by Wertheim from ""C. maculatum"". It crystallises in colourless leaflets, has a coniine-like odour, can be sublimed, and is strongly basic. It crystallises readily from ether. The salts are crystalline; the aurichloride small rhombs or prisms, mp. 133 °C; the benzoyl derivative mp. 132 °C. On oxidation with chromic acid, conhydrine yields -piperidyl-2-carboxylic acid. It is converted into -coniine either by reduction of the iodo-derivative (iodoconiine), CHIN, formed by the action of hydriodic acid and phosphorus at 180 °C or"
"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."
"to the marketing for Spice and K2 as incense. The hydrochloride salt exists as a very fine crystalline powder; it is hygroscopic and thus tends to form clumps, resembling something like powdered sugar. Its color can range from pure white to a yellowish-tan and has a slight odor that strengthens as it colors. Impurities are likely to consist of either pyrrolidine or alpha-dibrominated alkylphenones—respectively, from either excess pyrrolidine or incomplete amination during synthesis. These impurities likely account for its discoloration and fishy (pyrrolidine) or bromine-like odor, which worsens upon exposure to air, moisture, or bases. Methylenedioxypyrovalerone has no record of"