Chemistry Life in Daily Life Essay Example for Free

Chemistry Life in Daily Life Essay Introduction: Fluorine has the distinction of being the most reactive of all the elements, with the highest electronegativity value on the periodic table. Because of this, it proved extremely difficult to isolate. Davy first identified it as an element, but was poisoned while trying unsuccessfully to decompose hydrogen fluoride. Two other chemists were also later poisoned in similar attempts, and one of them died as a result. French chemist Edmond Fremy (1814-1894) very nearly succeeded in isolating fluorine, and though he failed to do so, he inspired his student Henri Moissan (1852-1907) to continue the project. One of the problems involved in isolating this highly reactive element was the fact that it tends to attack any container in which it is placed: most metals, for instance, will burst into flames in the presence of fluorine. Like the others before him, Moissan set about to isolate fluorine from hydrogen fluoride by means of electrolysis—the use of an electric current to cause a chemical reaction—but in doing so, he used a platinum-iridium alloy that resisted attacks by fluorine. In 1906, he received the Nobel Prize for his work, and his technique is still used today in modified form. Properties And Uses Of Fluorine: A pale green gas of low density, fluorine can combine with all elements except some of the noble gases. Even water will burn in the presence of this highly reactive substance. Fluorine is also highly toxic, and can cause severe burns on contact, yet it also exists in harmless compounds, primarily in the mineral known as fluorspar, or calcium fluoride. The latter gives off a fluorescent light (fluorescence is the term for a type of light not accompanied by heat), and fluorine was named for the mineral that is one of its principal hosts. Beginning in the 1600s, hydrofluoric acid was used for etching glass, and is still used for that purpose today in the manufacture of products such as light bulbs. The oil industry uses it as a catalyst—a substance that speeds along a chemical reaction—to increase the octane number in gasoline. Fluorine is also used in a polymer commonly known as Teflon, which provides a non-stick surface for frying pans and other cooking-related products. Just as chlorine saw service in World War I, fluorine was enlisted in World War II to create a weapon far 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 large quantities of the uranium-235 isotope. This they obtained in large part 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 concentration of fluoride in their drinking water tended to suffer a much lower incidence of tooth decay. In some areas the concentration of fluoride in the water supply was high enough that it stained peoples teeth; still, at the turn of the century—an era when dental hygiene as we know it today was still in its infancy—the prevention of tooth decay was an attractive prospect. Perhaps, officials surmised, it would be possible to introduce smaller concentrations of fluoride into community drinking water, with a resulting improvement in overall dental health. After World War II, a number of municipalities around the United States ndertook the fluoridation of their water supplies, using concentrations as low as 1 ppm. Within a few years, fluoridation became a hotly debated topic, with proponents pointing to the potential health benefits and opponents arguing from the standpoint of issues not directly involved in science. It was an invasion of personal 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—just another manifestation of a government trying to control its citizens. In later years, ironically, antifluoridation efforts became associated with groups on the political left rather than the right. By then, the argument no longer revolved around the issue of government power; instead the concern was for the health risks involved in introducing a substance lethal in large doses. Fluoride had meanwhile gained application in toothpastes. Colgate took the lead, introducing stannous fluoride in 1955. Three 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 announced Look, Ma!  No cavities! Within a few years, virtually all brands of toothpaste used fluoride; however, the use of fluoride in drinking water remained controversial. As late as 1993, in fact, the issue of fluoridation remained heated enough to spawn a study by the U. S. National Research Council. The council found some improvement in dental health, but 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 generally heightened awareness of dental health among the U.  S. populace. Chlorofluorocarbons : Another controversial application of fluorine is its use, along with chlorine and carbon, in chlorofluorocarbons. As noted above, CFCs have been used in refrigerants and propellants; another application is as a blowing agent for polyurethane foam. This continued for several decades, but in the 1980s, environmentalists became concerned over depletion of the ozone layer high in Earths atmosphere. Unlike ordinary oxygen (O 2 ), ozone or O 3 is capable of absorbing ultraviolet radiation from the Sun, which would otherwise be harmful to human life. It is believed that CFCs catalyze the conversion of ozone to oxygen, and that this may explain the ozone hole, which is particularly 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, have developed CFC substitutes, most notably hydrochlorofluorocarbons (HCFCs), CFC-like compounds also containing hydrogen atoms. The ozone-layer question is far from settled, however. 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 humans have been using CFCs. (Ozone depletion is far less significant in the Arctic, which is much closer to the population centers of the industrialized world. ) In any case, natural sources, such as volcano eruptions, continue to add halogen compounds to the atmosphere. Introduction: Chlorine is a highly poisonous gas, greenish-yellow in color, with a sharp smell that induces choking in humans. Yet, it can combine with other elements to form compounds safe for human consumption. Most notable among these compounds is salt, which has been used as a food preservative since at least 3000 B. C. Salt, of course, occurs in nature. By contrast, the first chlorine compound made by humans was probably hydrochloric acid, created by dissolving 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 medieval period. Alchemists, who in some ways were the precursors of true 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 mixture of hydrochloric and nitric acids known as aqua regia. The first modern scientist to work with chlorine was Swedish chemist Carl W. Scheele (1742-1786), who also discovered a number of other elements and compounds, including barium, manganese, oxygen, ammonia, and glycerin. However, Scheele, who isolated it in 1774, thought that chlorine was a compound; only in 1811 did English chemist Sir Humphry Davy (1778-1829) identify it as an element. Another chemist had suggested the name halogen for the alleged compound, but Davy suggested that it be called chlorine instead, after the Greek word chloros , which indicates a sickly yellow color. Uses Of Chlorine: The dangers involved with chlorine have made it an effective substance to use against stains, plants, animals—and even human beings. Chlorine gas is highly irritating to the mucous membranes of the nose, mouth, and lungs, and it can be detected in air at a concentration of only 3 parts per million (ppm). The concentrations of chlorine used against troops on both sides in World War I (beginning in 1915) was, of course, much higher. Thanks to the use of chlorine gas and other antipersonnel agents, one of the most chilling images to emerge from that conflict was of soldiers succumbing to poisonous gas. Yet just as it is harmful to humans, chlorine can be harmful to microbes, thus preserving human life. As early as 1801, it had been used in solutions as a disinfectant; in 1831, its use in hospitals made it effective as a weapon against a cholera epidemic that swept 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 get 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 effective—a good reason not to use regular old-fashioned bleach on anything other than white clothing. Since the 1980s, makers of bleaches have developed all-color versions to brighten and take out stains from clothing of other colors. ) Calcium hydrocholoride (CaOCl), both a bleaching powder and a disinfectant 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 compounds formed with the highly reactive element chlorine. Particularly notable—and controversial—are compounds involving chlorine and carbon. Chlorine And Organic Compounds: Chlorine 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 synthetic pipe. Chlorine polymers are also applied 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 because of concerns over health and the environment, and in some cases chlorine-carbon compounds have been outlawed. Such was the fate 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 likewise been banned due to their potential for harm to human life and the environment. Among these are chlorine-containing materials once used for dry cleaning. 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 evaporate 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 name is derived from a Greek word meaning stink. With a boiling point much lower than that of water—137. 84 °F (58. 8 °C)—it readily transforms into a gas. Like 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 Arkansas and Michigan. Credit for the isolation of bromine is usually 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 published his results a year later, provided a much more detailed explanation of bromines properties. The first use of bromine actually predated both men by several millennia. To make their famous purple dyes, the Phoenicians used murex mollusks, which contained bromine. (Like the names of the halogens, the word Phoenicians is derived from Greek—in this case, a word meaning 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 additive for gasoline containing lead. Ethylene dibromide reacts with the lead released by gasoline 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 Lamps: The 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 tungsten as the principal material in the filament, the area that is heated. Tungsten proved much more durable than carbon when heated, but it has a number of problems when combined with the gases in an incandescent bulb. As the light bulb continues to burn for a period of time, the tungsten filament begins to thin and will eventually break. At the same 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 filling—thus making a halogen lamp—these problems are alleviated. As tungsten evaporates from the filament, it combines with the halogen to form a gaseous 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 burns 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: First isolated in 1811 from ashes of seaweed, iodine has a name derived from the Greek word meaning violet-colored—a reference to the fact it forms dark purple crystals.  During the 1800s, iodine was obtained commercially from mines in Chile, but during the twentieth century wells 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 hormone that contains iodine, and lack of iodine can cause a goiter, a swelling around the neck. Table salt does not naturally contain iodine; however, sodium chloride sold in stores usually contains about 0. 01% sodium iodide, added by the manufacturer. Iodine 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 synthesis of organic compounds. Introduction: Just as 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 luck finding it in nature, and it was only created in 1940 by bombarding bismuth with alpha particles (positively charged 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 strange 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.

In The Movie tombstone, Friendship Comes In Different Forms :: essays research papers

In the Movie "Tombstone", Friendship Comes in Different Forms Friendship between two people can come in many different forms. In a companionship you could just be acquaintances, where at one time or another someone might have done something for you that might have changed your life for the better. To this individual you feel as if you owe them a favor in return. For this reason you would always help them in their time of need. In the movie Tombstone, Wyatt Earp was the only amigo that Doc Holiday ever had. So no matter when Wyatt was in trouble Doc was always there for him. For example the time all of Wyatts' brothers were murdered and Wyatt took revenge on the people who did it. So, even though on his death bed, Doc Holiday, got up and went with Wyatt to help him slay them. This is one way that a friendship can form between two people. A further example of the friendship between Wyatt and Holiday was when the Dalton gang had come into town with their guns and went into the O.K. Corral. They were going to get Wyatt for killing one for their brothers. Doc knew that Wyatt might of been killed if he went there on his own. So again, even though not in the best of health, Doc went to help Wyatt out. Another type of friendship is the one that came between John Oakhurst and young Tom Simson in the story of The Outcast of Poker Flat. In this camaraderie the two men were in a poker game and young Simson lost all of his money to Oakhurst. After the game Oakhurst pulled him aside and gave him his money back and a little lecture on not to gamble any more. By this he made a slave (friend) for life. A few months later when Oakhurst became exiled out of

Notes from Doran

How did concerns to keep Catholics happy Influence Elizabethan religious settlement? For both personal and political reasons Elizabeth was anxious to retain certain Catholic ceremonial traditions within her Church. Personally, she disliked the idea of a married clergy, she loved elaborate Church music and refused to accept that all images were idolatrous. Equally, she was aware that she had to persuade Spain that her Church was little different, externally, to theirs.At the same time, she had to persuade the Lutheran that she was a follower of their Suburb Confession. Therefore, outward Catholic signs such as the use of vestments, crosses and candlesticks would serve to reassure both Lutheran and Catholics. How widespread does Doran say Catholicism was up to 1 580? When Elizabeth came to the throne, the ma]royalty of people In England and Wales were Catholic in belief. By 1 559 only 14% of wills in Sussex contained Protestant formulae and bequests; by 1560 only 10% of wills in Kent h ad a statement of Protestantism in the preamble.Therefore, Elizabethan task was to slowly wean the population away from their traditional Catholic beliefs and towards her protestant gem through preaching and education. The government was actually particularly successful in this, reducing Catholicism to a mere household religion with only 1-2% of the population supporting it. Some say this was down to the gentry and clerical leadership's failure to mount any resistance to Elizabethan Religious Settlement, thus allowing ordinary laity to drift into conformity. When the parish priest was ready to use the Book of Common Prayer and the squire publicly appeared at the new services, it was hardly surprising the ordinary people followed the examples of their social superiors† Patrick McGrath The Catholic Church did not simply give in without a struggle when Elizabeth came to the throne. The Clerical leadership made an early start against Elizabethan settlement – the bishops' fo ught against the 1559 legislation In the House of Lords as well as the refusal of all but one of the Marina episcopate to take the Oath of Supremacy.Many of the Catholic Intelligentsia also refused to conform to the new Protestant Church – about 100 fellows and other senior members left the university of Oxford between 1559 – 1566. Corner of these went into exile, some went to the Catholic university of Alluvial publishing 40+ books and pamphlets between 1564- 1568. By 1564 Lavational attacks on the Elizabethan Church scared Elizabeth, and by 1 566 the Queen was so concerned about illegal foreign books entering the country, that she asked for all boats to be searched. What reasons does Doran give for Increasing perceived threat of Catholicism In the 1 5705? OFF England and abroad. The deteriorating relationship with Spain after 1568 and Mary Stuart flight to England in the same year to seek refuge led to many Catholic plots for uprising and rebellion supported by Spani sh military power. The 1566 election of Pope Pips V, who referred to Elizabeth as one Who pretended to be Queen of England', raised anxieties over whether he would send a crusade. Finally, in 1569 the Northern Rebellion broke out which vindicated fears of a Catholic threat; this was followed by the Bull of Excommunication in 1570 and the Riddled Plot in 1571.In 1572 the massacre of French Hugeness on SST. Bartholomew Day scared people that there was an international plot to wipe out Protestantism. How much a threat were Catholics in reality? Not huge, it has been exaggerated slightly. The people of England were mostly loyal to the Queen and Country, they simply hoped for better times under Mary. The Northern Rebellion was largely contained in the Northern counties of Durham, Northumberland, Wasteland and York. John Leslie and Nicholas Sanders were the only two polemicists to write books expressing political opposition.Equally, the government put more pressure on the Catholics which weakened their threat considerably: more enquiries were held into recusant, the Privy Council ordered new groups of people to subscribe to the Prayer Book and supremacy; ewers at the Inns of Court were questioned about their attendance at communion and many bishops took firmer action against recusant; Catholics were usually fined; some lawyers expelled from their Inns at Courts and some lost their position on the bench of magistrates.How loyal were Catholics in the 1 sass? Even though during the sass an intense persecution of their religion took place, Catholics were mostly loyal to Queen Elizabeth. The vast majority of people simply waited for better times ahead when Mary, Queen of Scots was to take to the throne or when they might be granted tolerance under Protestantism. Very few people plotted against Elizabeth or her government. Most people passively accepted laws for recusant and accepted those enforcing penal laws.There were several statements and petitions addressed to the Q ueen by prominent Catholics expressing their loyalty and not all were under duress. In fact, in 1585 Catholic nobles and gentry led by Thomas Howard, Duke of Norfolk presented Elizabeth with a petition stating their complete loyalty. Even after a call for the restoration of Catholicism by force from William Allen and Robert Parsons, there was very little Catholic support.

What Is an Icon in Rhetoric and Popular Culture

An icon can be defined as: (1) A representative picture or image: If something is iconic, it represents something else in a conventionalised way, as with features on a map (roads, bridges, etc.) or onomatopoeic words (as for example the words kersplat and kapow in U.S. comic books, standing for the impact of a fall and a blow). (Tom McArthur, The Oxford Companion to the English Language, 1992) (2) A person who is the object of great attention or devotion. (3) An enduring symbol. Iconography refers to the images collectively associated with a person or thing or to the study of images in the visual arts. Etymology -Â  From the Greek, likeness, image The Food Icon In an effort to simplify the message it gives the public on healthy eating, the federal government yesterday unveiled a new icon to replace the complicated and confusing food pyramid: It’s a plate divided into four sections, with fruits and vegetables on one half and protein and grains on the other. A circle for dairy—indicating a glass of milk or container of yogurt—rests to the right of the plate. The new icon is simple and easy to understand, with more emphasis placed on fruits and vegetables, Surgeon General Regina M. Benjamin said in a statement. It’s designed, she said, to help individuals and families make healthier meal choices. (Deborah Kotz, US Serves New ‘Plate’ of Food Choices. The Boston Globe, June 3, 2011) The Iconic 19th-Century Woman In an article titled Quiet Women appearing in Ladies Repository in 1868, an anonymous author argues that quiet women [are] the wine of life. Capturing the deep cultural longing of the postbellum period for the icon of the American woman as angel of the hearth, this portrait deifies the quiet woman and constructs other possibilities negatively: the enthusiastic woman, the talkative woman, the brilliant woman, and the babbling woman. The mild and mellow queen of the court of silence is graceful and calm, and most important of all, she is quiet. (Nan Johnson, Gender and Rhetorical space in American life, 1866-1910. Southern Illinois Univ. Press, 2002) Visual Rhetoric More than 60 percent of our grocery store purchases are impulse buying, which is primarily a result of packaging—the way the product looks and its placement on the shelves. Ronald McDonald is second only to Santa Claus as a recognized icon by Americans. At sporting events, in concert halls, political rallies, even in our houses of worship, eyes turn away from the real event as soon as images begin to move on giant screens. Some critics insist that television itself has been transformed since the 1980s from a word-based rhetoric with minimal production values to a visually based mythic rhetoric that uses sophisticated production techniques to project an extreme self-consciousness of style. (Karlyn Kohrs Campbell and Suszn Schultz Huxman, The Rhetorical Act: Thinking, Speaking and Writing Critically, 4th ed. Wadsworth Cengage, 2009) Icons and Symbols in Advertising All representational images are icons. But many icons are also symbols. If in addition to its mimetic relationship to a referent, the thing pictured has, by social agreement, certain arbitrary meanings, it will be both an icon and a symbol. For example, a bald eagle icon will always have a mimetic relationship with its referent animal and, in an ad, it might signify mimetically fierceness, wildness, and unspoiled natural settings. But in some ads, the eagle may also, by arbitrary convention, symbolically signify the United States or the Boy Scouts. One reason why most ad images are rhetorically rich is because the things pictured in the ad have both literal/iconic and arbitrary/symbolic dimensions of meaning. (Edward F. McQuarrie, Go Figure: New Directions in Advertising Rhetoric. M.E. Sharpe, 2008) Icons Arent What They Used to Be Icons are increasingly hard to avoid. Last month I attended a funeral at which a mourner referred to the deceased as a local icon. While visiting Dublin in June, I found myself dining with a Scottish author of terrifying murder mysteries who described herself as an international cultural icon. I also read in the press that McDonalds was an iconic franchise. Then I got an email announcing that Creative Artists Agency had just added Greg Norman to its roster of clients. That is, Greg Norman, international golf icon. The term icon has two basic meanings, neither of which apply to Michael Jackson, Greg Norman, Ed McMahon, most Scottish mystery writers or anyone from Paul Revere the Raiders. Originally it referred to sacred images painted on tiny wooden panels back in the days of the Eastern Empire. Thus, in theory, Farrah Fawcetts famous 70s poster could vaguely qualify as an icon. But for the longest time the word icon was used to refer to what Websters describes as an object of uncritical devotion. No more. Today it is used to describe anyone reasonably famous who is completely over the hill, on a respirator, or stone dead. Or, in the case of Mickey Ds, beloved but inanimate. . . . This is just another case of hyperventilating journalists hijacking an otherwise admirable language because they are desperate to insert an infectious banality into their work and dont care if it belongs there. (Joe Queenan, Icons Arent What They Used to Be. The Wall Street Journal, July 20, 2009) More on Symbolic Language and Imagery EmojiEmoticonIdeogramImagerySemioticsSignVisual MetaphorVisual RhetoricVogue Word