Chemistry Life in Daily Life Essay

Introduction Fluorine has the government none of being the just about labile of solely the subdivisions, with the highest electr binglegativity value on the half-hourly table. Be reach of this, it proved extremely difficult to seize. Davy set-back identified it as an element, however was embittered bit arduous unsuccessfully to decompose heat content fluoride. Two premature(a) pill rollers were also afterwardsward pois stard in similar attempts, and one of them died as a result. French chemist Edmond Fremy (1814-1894) really nearly succeeded in isolating atomic spot 9, and though he fai take to do so, he godly his student Henri Moissan (1852-1907) to continue the project.One of the problems re recently in isolating this extremely reactive element was the fact that it tends to attack whatsoever container in which it is placed most metals, for instance, allow for burst into fervidnesss in the presence of fluorine. want the any(prenominal) early(a)s f orwards him, Moissan set about to isolate fluorine from hydrogen fluoride by manner of electrolysisthe role of an electric current to ca utilize a chemical substance reaction scarce in doing so, he apply a platinum-iridium alloy that resisted attacks by fluorine. In 1906, he received the Nobel Prize for his trim, and his technique is lighten utilize today in limited form.Properties And Uses Of Fluorine A pale cat valium splash of low density, fluorine domiciliate assent with all elements except any(prenominal) of the noble gases. Even pissing will burn in the presence of this extremely reactive substance. Fluorine is also extremely toxic, and female genital organ ca hire severe ruin on contact, yet it also exists in ill-treatless(prenominal) changes, in general in the min successionl distinguishn as fluorspar, or calcium fluoride. The latter gives off a light light (fluorescence is the term for a compositors case of light not accompanied by heat), and fluorin e was take a shitd for the mineral that is one of its monger hosts.Beginning in the 1600s, hydrofluoric acid was apply for etching glass, and is still utilize for that usance today in the manufacture of products such as light myelins. The oil diligence usages it as a catalysta substance that speeds on a chemical reactionto increase the octane flake in gasoline. Fluorine is also employ in a polymer comm lonesome(prenominal) known as Teflon, which provides a non-stick go up for frying pans and other cooking- cerebrate products. Just as centiliter dictum service in sphere contend I, fluorine was enlisted in World contend II to create a sleeve farther more terrifying than poison gas the atomic bomb.Scientists working on the Manhattan Project, the United States effort to develop the bombs dropped on Japan in 1945, needed intumescent quantities of the uranium-235 isotope. This they obtained in large break open by diffusion of the compound uranium hexafluoride, which consists of molecules containing one uranium atom and six fluorine anions. Fluoridation Of Water Long before World War II, health officials in the United States noticed that communities having high constriction of fluoride in their drinking water tended to make a often lower relative incidence of tooth decay.In some beas the c one timentration of fluoride in the water supply was high plenty that it stained great deals tee rationaliseg still, at the turn of the centuryan era when dental hygiene as we know it today was still in its early childhoodthe prevention of tooth decay was an attractive prospect. Perhaps, officials surmised, it would be possible to introduce smaller concentrations of fluoride into fellowship drinking water, with a resulting improvement in overall dental health.After World War II, a number of municipalities approximately the United States ndertook the fluoridation of their water supplies, employ concentrations as low as 1 ppm. Within a few years, f luoridation became a hotly debated topic, with proponents pointing to the potential health benefits and opponents arguing from the standpoint of issues not straight off multiform in science. It was an invasion of face-to-face liberty, they said, for governments to force citizens to drink water which had been supplemented with a foreign substance. During the 1950s, in fact, fluoridation became associated in some circles with Communism vertical other manifestation of a government trying to control its citizens.In later years, campaignically, antifluoridation efforts became associated with groups on the political left kinda than the right. By indeed, the argument no interminable go approximately around the issue of government personnel instead the concern was for the health risks touch in introducing a substance lethal in large doses. Fluoride had meanwhile gained drill in toothpastes. Colgate took the lead, introducing stannous fluoride in 1955. terzetto years later, the company launched a memorable advertising campaign with commercials in which a little girl showed her mother a report card from the dentist and denote Look, MaNo cavities Within a few years, virtually all brands of toothpaste apply fluoride however, the use of fluoride in drinking water remained polemic. As late as 1993, in fact, the issue of fluoridation remained heated exuberant to spawn a study by the U. S. National Research Council. The council found some improvement in dental health, unless not as large as had been claimed by early proponents of fluoridation. Furthermore, this improvement could be explained by reference to a number of other factors, including fluoride in toothpastes and a broadly heightened awareness of dental health among the U.S. populace.Chlorofluoro carbon copys other controversial application of fluorine is its use, along with atomic number 17 and carbon, in chlorofluorocarbons. As state above, CFCs demand been apply in refrigerants and propell ants other application is as a blowing cistron for polyurethane foam. This continued for several decades, unless in the 1980s, environmentalists became concerned over depletion of the ozone storey high in balls atmosphere. Unlike ordinary oxygen (O 2 ), ozone or O 3 is receptive of absorbing ultraviolet radiation from the Sun, which would other be harmful to pitying life.It is believed that CFCs catalyze the conversion of ozone to oxygen, and that this whitethorn explain the ozone hole, which is specially noticeable over the Antarctic in September and October. As a result, a number of countries signed an agreement in 1996 to eliminate the manufacture of halocarbons, or substances containing halogens and carbon. Manufacturers in countries that signed this agreement, known as the Montreal Protocol, digest actual CFC substitutes, most notably hydrochlorofluorocarbons (HCFCs), CFC-like compounds also containing hydrogen atoms.The ozone- storey question is far from settled, h owever. Critics argue that in fact the depletion of the ozone layer over Antarctica is a natural occurrence, which may explain why it only occurs at certain times of year. This may also explain why it happens primarily in Antarctica, far from any place where universe admit been using CFCs. (Ozone depletion is far less signifi goatt in the Arctic, which is frequently walk-to(prenominal) to the population centers of the industrialized world. ) In any case, natural sources, such as outlet eruptions, continue to add halogen compounds to the atmosphere.Introduction atomic number 17 is a highly poisonous gas, greenish- color in color, with a sharp smell that induces strangling in military man. Yet, it privy combine with other elements to form compounds safe for clement consumption. intimately guiding light among these compounds is table salt, which has been used as a food preservative since at to the lowest degree 3000 B. C. Salt, of course, occurs in nature. By contrast, the first centilitre compound do by humans was probably hydrochloric acid, created by dissipation hydrogen chloride gas in water.The first scientist to work with hydrochloric acid was Persian physician and alchemist Rhazes (ar-Razi c. 64-c. 935), one of the most outstanding scientific minds of the gothic period. Alchemists, who in some ways were the precursors of square chemists, believed that base metals such as iron could be turned into gold. Of course this is not possible, but alchemists in about 1200 did at least succeed in dissolving gold using a admixture of hydrochloric and nitric acids known as cobalt ultramarine regia. The first modern scientist to work with atomic number 17 was Swedish chemist Carl W. Scheele (1742-1786), who also find a number of other elements and compounds, including barium, manganese, oxygen, ammonia, and glycerin.However, Scheele, who uninvolved it in 1774, thought that chlorine was a compound only in 1811 did incline chemist Sir Humphry Davy ( 1778-1829) identify it as an element. another(prenominal) chemist had suggested the recognise halogen for the alleged compound, but Davy suggested that it be called chlorine instead, after the classical word chloros , which indicates a sickly yellow color. Uses Of Chlorine The dangers involved with chlorine meet made it an effective substance to use against stains, plants, animalsand even human beings.Chlorine gas is highly irritating to the mucous membranes of the nose, mouth, and lungs, and it can be detected in pipeline at a concentration of only 3 parts per million (ppm). The concentrations of chlorine used against troops on twain sides in World War I (beginning in 1915) was, of course, overmuch higher. Thanks to the use of chlorine gas and other antipersonnel agents, one of the most chilling images to go forth from that conflict was of changeiers succumbing to poisonous gas. Yet just as it is harmful to humans, chlorine can be harmful to microbes, thereof preserving hu man life.As early as 1801, it had been used in solutions as a antimicrobial in 1831, its use in hospitals made it effective as a weapon against a cholera epidemic that move across Europe. Another well-known use of chlorine is as a bleaching agent. Until 1785, when chlorine was first put to use as a bleach, the only way to put up stains and unwanted colors out of textiles or paper was to expose them to sunlight, not always an effective method.By contrast, chlorine, still used as a bleach today, can be highly effectivea good reason not to use regular old-fashioned bleach on anything other than white wearable. Since the 1980s, makers of bleaches have highly-developed all-color versions to brighten and take out stains from clothing of other colors. ) Calcium hydrocholoride (CaOCl), both a bleaching powder and a germicidal used in swimming pools, combines both the disinfectant and bleaching properties of chlorine. This and the others discussed here are just some of many, many compo unds formed with the highly reactive element chlorine. Particularly notableand controversialare compounds involving chlorine and carbon. Chlorine And extreme CompoundsChlorine bonds well with organic substances, or those containing carbon. In a number of instances, chlorine becomes part of an organic polymer such as PVC (polyvinyl chloride), used for making synthetical pipe. Chlorine polymers are also employ in making synthetic rubber, or neoprene. Due to its resistance to heat, oxidation, and oils, neoprene is used in a number of automobile parts. The bonding of chlorine with substances containing carbon has become increasingly controversial be prepare of concerns over health and the environment, and in some cases chlorine-carbon compounds have been outlawed.Such was the destiny of DDT, a pesticide soluble in fats and oils rather than in water. When it was discovered that DDT was carcinogenic, or cancer-causing, in humans and animals, its use in the United States was outlawed. Other, less well-known, chlorine-related insecticides have withal been banned due to their potential for harm to human life and the environment. Among these are chlorine-containing materials once used for dry newing. Also notable is the role of chlorine in chlorofluorocarbons (CFCs), which have been used in refrigerants such as Freon, and in propellants for aerosol sprays.CFCs tend to vaporise easily, and concerns over their effect on Earths atmosphere have led to the phasing out of their use.Introduction Bromine is a foul-smelling reddish-brown liquid whose note is derived from a classical word sum stink. With a boiling point much lower than that of water137. 84F (58. 8C)it readily transforms into a gas. equivalent other halogens, its vapors are highly irritating to the eyes and throat. It is found primarily in deposits of brine, a solution of salt and water. Among the most significant brine deposits are in Israels Dead Sea, as well as in are and Michigan.Credit for the i solation of atomic number 35 is unremarkably given to French chemist Antoine-Jerome Balard (1802-1876), though in fact German chemist Carl Lowig (1803-1890) actually isolated it first, in 1825. However, Balard, who promulgated his results a year later, provided a much more detailed explanation of atomic number 35s properties. The first use of bromine actually predated both men by several millennia. To make their famous purplish dyes, the Phoenicians used murex mollusks, which contained bromine. (Like the names of the halogens, the word Phoenicians is derived from Greekin this case, a word importation red or purple, which referred to their dyes.Today bromine is also used in dyes, and other modern uses include applications in pesticides, disinfectants, medicines, and flame retardants. At one time, a compound containing bromine was widely used by the petroleum industry as an one- smutchensional for gasoline containing lead. Ethylene di platitude reacts with the lead released by g asoline to form lead bromide (PbBr 2 ), referred to as a scavenger, because it tends to clean the emissions of lead-containing gasoline. However, leaded gasoline was phased out during the late 1970s and early 1980s as a result, demand for ethylene dibromide dropped considerably. Halogen LampsThe name halogen is probably familiar to most people because of the term halogen lamp. Used for automobile headlights, spotlights, and floodlights, the halogen lamp is much more effective than ordinary incandescent light. Incandescent heat-producing light was first developed in the 1870s and improved during the early part of the twentieth century with the replacement of carbon by watt as the headway material in the filament, the ambit that is heated. tungsten proved much more constant than carbon when heated, but it has a number of problems when combined with the gases in an incandescent myelin.As the light bulb continues to burn for a period of time, the tungsten filament begins to thin and will eventually break. At the similar time, tungsten begins to accumulate on the surface of the bulb, dimming its light. However, by adding bromine and other halogens to the bulbs gas fillingthus making a halogen lampthese problems are alleviated. As tungsten evaporates from the filament, it combines with the halogen to form a vaporish compound that circulates within the bulb. Instead of depositing on the surface of the bulb, the compound remains a gas until it comes into contact with the filament and breaks down.It is then redeposited on the filament, and the halogen gas is free to combine with newly evaporated tungsten. Though a halogen bulb does eventually break down, it lasts much longer than an ordinary incandescent bulb and destroy with a much brighter light. Also, because of the decreased tungsten deposits on the surface, it does not begin to dim as it nears the end of its life.Introduction rootage isolated in 1811 from ashes of seaweed, iodine has a name derived from the Greek word core violet-coloreda reference to the fact it forms patrician purple crystals.During the 1800s, iodine was obtained commercially from mines in Chile, but during the twentieth century surface of brine in Japan, Oklahoma, and Michigan have proven a better source. Uses And Applications Among the best-known properties of iodine is its importance in the human diet. The thyroid gland produces a growth-regulating internal secretion that contains iodine, and lack of iodine can cause a goiter, a swelling around the neck. Table salt does not of course contain iodine however, atomic number 11 chloride sold in stores usually contains about 0. 01% sodium iodide, added by the manufacturer. ace was once used in the development of photography During the early days of photographic technology, the daguerreotype process used silver plates sensitized with iodine vapors. Iodine compounds are used today in chemical analysis and in entailment of organic compounds.Introduction Just a s fluorine has the distinction of being the most reactive, astatine is the rarest of all the elements. Long after its existence was predicted, chemists still had no mint finding it in nature, and it was only created in 1940 by bombarding bismuth with alpha particles (positively supercharged helium nuclei).The newly isolated element was given a Greek name meaning unstable. Indeed, none of astatines 20 known isotopes is stable, and the longest-lived has a half-life of only 8. 3 hours. This has only added to the difficulties involved in learning about this gothic element, and therefore it is difficult to say what applications, if any, astatine may have. The most promising area involves the use of astatine to treat a condition known as hyperthyroidism, related to an overly active thyroid gland.