"structure is cubic. Arsenic, antimony, and bismuth all have rhombohedral crystal structures. The nitrogen compound sal ammoniac (ammonium chloride) has been known since the time of the Ancient Egyptians. In the 1760s two scientists, Henry Cavendish and Joseph Priestley, isolated nitrogen from air, but neither realized the presence of an undiscovered element. It was not until several years later, in 1772, that Daniel Rutherford realized that the gas was indeed nitrogen. The scientist Hennig Brandt first discovered phosphorus in Hamburg in 1669. Brandt produced the element by heating evaporated urine and condensing the resulting phosphorus vapor in water. Brandt initially"
"and inhibit pain signalling. Exactly how causes the release of endogenous opioid peptides remains uncertain. Nitrous oxide is a colourless, non-toxic gas with a faint, sweet odour. Nitrous oxide supports combustion by releasing the dipolar bonded oxygen radical, thus it can relight a glowing splint. The above reaction is the route adopted by the commercial chemical industry to produce azide salts, which are used as detonators. The gas was first synthesised in 1772 by English natural philosopher and chemist Joseph Priestley, who called it ""phlogisticated nitrous air"" (see phlogiston) or ""inflammable nitrous air"". Priestley published his discovery in the book"
"scientific discovery in 1774, arguably more revolutionary than his isolation of oxygen. He identified lime, silica, and iron in a specimen of pyrolusite (impure manganese dioxide) given to him by his friend, Johann Gottlieb Gahn, but could not identify an additional component (this was the manganese, which Scheele recognized was present as a new element, but could not isolate). When he treated the pyrolusite with hydrochloric acid over a warm sand bath, a yellow-green gas with a strong odor was produced. He found that the gas sank to the bottom of an open bottle and was denser than ordinary air."
"by heating mercuric oxide and nitrates in 1771, but did not publish his findings until 1777. Priestley also prepared this new ""air"" by 1774, but only Lavoisier recognized it as a true element; he named it in 1777. Nitrogen: Rutherford discovered nitrogen while he was studying at the University of Edinburgh. He showed that the air in which animals breathed, after removal of exhaled carbon dioxide, was no longer able to burn a candle. Scheele, Henry Cavendish, and Priestley also studied this element at about the same time; Lavoisier named it in 1775 or 1776. Tellurium: In 1783, Franz-Joseph Müller"
"Middle Ages. Alchemists knew nitric acid as ""aqua fortis"" (strong water), as well as other nitrogen compounds such as ammonium salts and nitrate salts. The mixture of nitric and hydrochloric acids was known as ""aqua regia"" (royal water), celebrated for its ability to dissolve gold, the king of metals. The discovery of nitrogen is attributed to the Scottish physician Daniel Rutherford in 1772, who called it ""noxious air"". Though he did not recognise it as an entirely different chemical substance, he clearly distinguished it from Joseph Black's ""fixed air"", or carbon dioxide. The fact that there was a component of"
"water molecules. Ions, such as , and excited-state complexes, such as ArF, have been demonstrated. Theoretical calculation predicts several more argon compounds that should be stable but have not yet been synthesized. ""Argon"" (Greek , neuter singular form of meaning ""lazy"" or ""inactive""), is named in reference to its chemical inactivity. This chemical property of this first noble gas to be discovered impressed the namers. An unreactive gas was suspected to be a component of air by Henry Cavendish in 1785. Argon was first isolated from air in 1894 by Lord Rayleigh and Sir William Ramsay at University College London"
"peculiarly light and easy for some time afterwards."" Priestley published his findings in 1775 in a paper titled ""An Account of Further Discoveries in Air,"" which was included in the second volume of his book titled ""Experiments and Observations on Different Kinds of Air"". Because he published his findings first, Priestley is usually given priority in the discovery. The French chemist Antoine Laurent Lavoisier later claimed to have discovered the new substance independently. Priestley visited Lavoisier in October 1774 and told him about his experiment and how he liberated the new gas. Scheele also dispatched a letter to Lavoisier on"
"known for smelling somewhat comparable to cannabis. It can be prepared by reacting carbon tetrachloride with hydrogen fluoride in the presence of a catalytic amount of antimony pentachloride: This reaction can also produce trichlorofluoromethane (CClF), chlorotrifluoromethane (CClF) and tetrafluoromethane (CF). Charles (Boss) Kettering, vice president of General Motors Research Corporation, was seeking a refrigerant replacement that would be colorless, odorless, tasteless, nontoxic, and nonflammable. He assembled a team that included Thomas Midgley, Jr., Albert Leon Henne, and Robert McNary. From 1930 to 1935, they developed dichlorodifluoromethane (CClF or R12), trichlorofluoromethane (CClF or R11), chlorodifluoromethane (CHClF or R22), trichlorotrifluoroethane (CClFCClF or"
"he sent to his publisher in 1775. That document was published in 1777. In the meantime, on August 1, 1774, an experiment conducted by the British clergyman Joseph Priestley focused sunlight on mercuric oxide (HgO) contained in a glass tube, which liberated a gas he named ""dephlogisticated air"". He noted that candles burned brighter in the gas and that a mouse was more active and lived longer while breathing it. After breathing the gas himself, Priestley wrote: ""The feeling of it to my lungs was not sensibly different from that of common air, but I fancied that my breast felt"
"in chemical compounds was lower than that of nitrogen found in the atmosphere. He ascribed this discrepancy to a light gas included in chemical compounds of nitrogen, while Ramsay suspected a hitherto undiscovered heavy gas in atmospheric nitrogen. Using two different methods to remove all known gases from air, Ramsay and Lord Rayleigh were able to announce in 1894 that they had found a monatomic, chemically inert gaseous element that constituted nearly 1 percent of the atmosphere; they named it argon. The following year, Ramsay liberated another inert gas from a mineral called cleveite; this proved to be helium, previously"
"first synthesized in 1772 by the natural philosopher and chemist Joseph Priestley, who called it ""phlogisticated nitrous air"" (see phlogiston). Priestley described his discovery in the book ""Experiments and Observations on Different Kinds of Air (1775)"", in which he described how to produce the preparation of ""nitrous air diminished"", by heating iron filings dampened with nitric acid. James Watt built a portable gas chamber to facilitate Davy's experiments with the inhalation of nitrous oxide. At one point the gas was combined with wine to judge its efficacy as a cure for hangover (his laboratory notebook indicated success). The gas was"
"the usage of ""green gas"", stating that its usage is ""internationally banned"". Adamsite Adamsite or DM is an organic compound; technically, an arsenical diphenylaminechlorarsine, that can be used as a riot control agent. DM belongs to the group of chemical warfare agents known as vomiting agents or sneeze gases. First synthesized in Germany by Heinrich Otto Wieland in 1915, it was independently developed by the US chemist Roger Adams (for whom it is named) at the University of Illinois in 1918. DM is an odourless crystalline compound with a very low vapour pressure. The colour of the crystals ranges from"
"the unusual effects of nitrous oxide, which came to be known as laughing gas. Chlorine was discovered in 1774 by Swedish chemist Carl Wilhelm Scheele, who called it """"dephlogisticated marine acid"""" (see phlogiston theory) and mistakenly thought it contained oxygen. Scheele observed several properties of chlorine gas, such as its bleaching effect on litmus, its deadly effect on insects, its yellow-green colour, and the similarity of its smell to that of aqua regia. However, Scheele was unable to publish his findings at the time. In 1810, chlorine was given its current name by Humphry Davy (derived from the Greek word"
"Nitrous oxide Nitrous oxide, commonly known as laughing gas or nitrous, is a chemical compound, an oxide of nitrogen with the formula . At room temperature, it is a colourless non-flammable gas, with a slight metallic scent and taste. At elevated temperatures, nitrous oxide is a powerful oxidizer similar to molecular oxygen. It is soluble in water. Nitrous oxide has significant medical uses, especially in surgery and dentistry, for its anaesthetic and pain reducing effects. Its name ""laughing gas"", coined by Humphry Davy, is due to the euphoric effects upon inhaling it, a property that has led to its recreational"
"explosive RDX. The transportation of dinitromethane is forbidden by the U.S. Department of Transportation. Dinitromethane Dinitromethane is an organic compound with the chemical formula CH(NO). Purified dinitromethane is a colorless liquid with a weak pleasant odor. It is relatively stable at room temperature and can be safely stored for months at 0 °C. The potassium salt of dinitromethanide, KCH(NO), was first prepared by Villiers in 1884 by reduction of bromodinitromethane. Hydrogen fluoride and the potassium salt of dinitromethane react in diethyl ether to form dinitromethane. Free dinitromethane was previously understood to be a pale, yellow oil that decomposed rapidly at"
"distributors were required to add thiols, originally ethanethiol, to natural gas (which is naturally odorless) after the deadly New London School explosion in New London, Texas, in 1937. Many gas distributors were odorizing gas prior to this event. Most gas odorants utilized currently contain mixtures of mercaptans and sulfides, with ""t""-butyl mercaptan as the main odor constituent in natural gas and ethanethiol in liquefied petroleum gas (LPG, propane). In situations where thiols are used in commercial industry, such as liquid petroleum gas tankers and bulk handling systems, an oxidizing catalyst is used to destroy the odor. A copper-based oxidation catalyst"
"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"
"Carbon tetrachloride Carbon tetrachloride, also known by many other names (the most notable being tetrachloromethane, also recognized by the IUPAC, carbon tet in the cleaning industry, Halon-104 in firefighting, and Refrigerant-10 in HVACR) is an organic compound with the chemical formula CCl. It was formerly widely used in fire extinguishers, as a precursor to refrigerants and as a cleaning agent. It is a colourless liquid with a ""sweet"" smell that can be detected at low levels. It has practically no flammability at lower temperatures. Carbon tetrachloride was originally synthesized by the French chemist Henri Victor Regnault in 1839 by the"
"Peter Woulfe Peter Woulfe (1727 – 1803) was an Irish chemist and mineralogist. He first had the idea that wolframite might contain a previously undiscovered element (tungsten). In 1771, Woulfe reported the formation of a yellow dye when indigo was treated with nitric acid. Later it was discovered by others that he had formed picric acid, which eventually was used as the first synthetic dye, an explosive and an antiseptic treatment for burns. Woulfe is credited with inventing, ca. 1767, the Woulfe Bottle, an apparatus for purifying or dissolving gases, which employed a bottle with two or three necks. Woulfe"
"Humphry Davy Sir Humphry Davy, 1st Baronet (17 December 177829 May 1829) was a Cornish chemist and inventor, who is best remembered today for isolating, using electricity, a series of elements for the first time: potassium and sodium in 1807 and calcium, strontium, barium, magnesium and boron the following year, as well as discovering the elemental nature of chlorine and iodine. He also studied the forces involved in these separations, inventing the new field of electrochemistry. In 1799 Davy experimented with nitrous oxide and became astonished that it made him laugh, so he nicknamed it ""laughing gas"", and wrote about"
"found that water treated in this manner had a pleasant taste, and he offered it to his friends as a refreshing drink. In 1772, Priestley published a paper entitled ""Impregnating Water with Fixed Air"" in which he describes dripping ""oil of vitriol"" (or sulfuric acid as it is now called) onto chalk to produce carbon dioxide gas, and encouraging the gas to dissolve into an agitated bowl of water. Another Englishman, John Mervin Nooth, improved Priestley's design and sold his apparatus for commercial use in pharmacies. Swedish chemist Torbern Bergman invented a generating apparatus that made carbonated water from chalk"
"water. Some authors credit Cruickshank with first suspecting an unknown substance in a Scottish mineral, strontianite, found near Strontian, in Argyleshire. Other authors name Adair Crawford for the discovery of this new earth, due to the mineral's property of imparting a redding color to a flame. It was later isolated by Humphry Davy and is now known as strontium. Cruikshank worked with John Rollo at Woolwich in the 1790s, and some of his discoveries about diabetes were published in Rollo's book on the dietary treatment of the condition. This research led him to isolate urea in 1798, though his priority"
"in London. Neon was discovered when Ramsay chilled a sample of air until it became a liquid, then warmed the liquid and captured the gases as they boiled off. The gases nitrogen, oxygen, and argon had been identified, but the remaining gases were isolated in roughly their order of abundance, in a six-week period beginning at the end of May 1898. First to be identified was krypton. The next, after krypton had been removed, was a gas which gave a brilliant red light under spectroscopic discharge. This gas, identified in June, was named ""neon"", the Greek analogue of ""novum"" (new),"
"in 1960. During the muon's lifetime, muonium can enter into compounds such as muonium chloride (MuCl) or sodium muonide (NaMu), analogous to hydrogen chloride and sodium hydride respectively. In 1671, Robert Boyle discovered and described the reaction between iron filings and dilute acids, which results in the production of hydrogen gas. In 1766, Henry Cavendish was the first to recognize hydrogen gas as a discrete substance, by naming the gas from a metal-acid reaction ""inflammable air"". He speculated that ""inflammable air"" was in fact identical to the hypothetical substance called ""phlogiston"" and further finding in 1781 that the gas produces"
"welfare of the adepts."" Peter Woulfe Peter Woulfe (1727 – 1803) was an Irish chemist and mineralogist. He first had the idea that wolframite might contain a previously undiscovered element (tungsten). In 1771, Woulfe reported the formation of a yellow dye when indigo was treated with nitric acid. Later it was discovered by others that he had formed picric acid, which eventually was used as the first synthetic dye, an explosive and an antiseptic treatment for burns. Woulfe is credited with inventing, ca. 1767, the Woulfe Bottle, an apparatus for purifying or dissolving gases, which employed a bottle with two"
"Davy, wrote to Davies Gilbert, ""I am now as much convinced of the non-existence of caloric as I am of the existence of light."" In another letter to Gilbert, on 10 April, Davy informs him: ""I made a discovery yesterday which proves how necessary it is to repeat experiments. The gaseous oxide of azote (the laughing gas) is perfectly respirable when pure. It is never deleterious but when it contains nitrous gas. I have found a mode of making it pure."" He said that he breathed sixteen quarts of it for nearly seven minutes, and that it ""absolutely intoxicated me."""
"(He) is a colorless, odorless, tasteless, non-toxic, inert monatomic chemical element that heads the noble gas series in the periodic table and whose atomic number is 2. Its boiling and melting points are the lowest among the elements and it exists only as a gas except in extreme conditions. Helium was discovered in 1868 by French astronomer Pierre Janssen, who first detected the substance as an unknown yellow spectral line signature in light from a solar eclipse. In 1903, large reserves of helium were found in the natural gas fields of the United States, which is by far the largest"
"people thought this gas to be lethal, even in small doses, like some other nitrogen oxides. However, in 1799, British chemist and inventor Humphry Davy decided to find out by experimenting on himself. To his astonishment he found that nitrous oxide made him laugh, so he nicknamed it ""laughing gas"". In 1800 Davy wrote about the potential anesthetic properties of nitrous oxide in relieving pain during surgery, but nobody at that time pursued the matter any further. American physician Crawford W. Long noticed that his friends felt no pain when they injured themselves while staggering around under the influence of"
"James Prescott Joule and William Thomson, 1st Baron Kelvin, who discovered it in 1852. It followed upon earlier work by Joule on Joule expansion, in which a gas undergoes free expansion in a vacuum and the temperature is unchanged, if the gas is ideal. The ""adiabatic"" (no heat exchanged) expansion of a gas may be carried out in a number of ways. The change in temperature experienced by the gas during expansion depends not only on the initial and final pressure, but also on the manner in which the expansion is carried out. The temperature change produced during a Joule–Thomson"
"William Ramsay Sir William Ramsay, (; 2 October 1852 – 23 July 1916) was a Scottish chemist who discovered the noble gases and received the Nobel Prize in Chemistry in 1904 ""in recognition of his services in the discovery of the inert gaseous elements in air"" (along with his collaborator, John William Strutt, 3rd Baron Rayleigh, who received the Nobel Prize in Physics that same year for their discovery of argon). After the two men identified argon, Ramsay investigated other atmospheric gases. His work in isolating argon, helium, neon, krypton and xenon led to the development of a new section"
"William Ramsay Sir William Ramsay, (; 2 October 1852 – 23 July 1916) was a Scottish chemist who discovered the noble gases and received the Nobel Prize in Chemistry in 1904 ""in recognition of his services in the discovery of the inert gaseous elements in air"" (along with his collaborator, John William Strutt, 3rd Baron Rayleigh, who received the Nobel Prize in Physics that same year for their discovery of argon). After the two men identified argon, Ramsay investigated other atmospheric gases. His work in isolating argon, helium, neon, krypton and xenon led to the development of a new section"
"Dinitromethane Dinitromethane is an organic compound with the chemical formula CH(NO). Purified dinitromethane is a colorless liquid with a weak pleasant odor. It is relatively stable at room temperature and can be safely stored for months at 0 °C. The potassium salt of dinitromethanide, KCH(NO), was first prepared by Villiers in 1884 by reduction of bromodinitromethane. Hydrogen fluoride and the potassium salt of dinitromethane react in diethyl ether to form dinitromethane. Free dinitromethane was previously understood to be a pale, yellow oil that decomposed rapidly at ambient temperatures. Dinitromethane is also produced as a byproduct from the production of the"
"air that does not support combustion was clear to Rutherford, although he was not aware that it was an element. Nitrogen was also studied at about the same time by Carl Wilhelm Scheele, Henry Cavendish, and Joseph Priestley, who referred to it as ""burnt air"" or ""phlogisticated air"". Nitrogen gas was inert enough that Antoine Lavoisier referred to it as ""mephitic air"" or ""azote"", from the Greek word (azotikos), ""no life"". In an atmosphere of pure nitrogen, animals died and flames were extinguished. Though Lavoisier's name was not accepted in English, since it was pointed out that almost all gases"