Mercury Facts - Periodic Table of the Elements

Mercury Facts - Periodic Table of the Elements Mercury is the only metallic element that is a liquid at room temperature. This dense metal is atomic number 80 with element symbol Hg. This collection of mercury facts includes atomic data, the electron configuration, chemical and physical properties, and history of the element. Mercury Basic Facts Symbol: HgAtomic Number: 80Atomic Weight: 200.59Element Classification: Transition MetalCAS Number: 7439-97-6Mercury Periodic Table LocationGroup: 12Period: 6Block: d Mercury Electron Configuration Short Form: [Xe]4f145d106s2Long Form: 1s22s22p63s23p63d104s24p64d105s25p64f145d106s2Shell Structure: 2 8 18 32 18 2 Mercury Discovery Discovery Date: Known to the ancient Hindus and Chinese. Mercury has been found in Egyptian tombs dating to 1500 B.C.Name: Mercury derives its name from the association between the planet Mercury and its use in alchemy. The alchemical symbol for mercury was the same for the metal and the planet. The element symbol, Hg, is derived from the Latin name hydragyrum meaning water silver. Mercury Physical Data State at room temperature (300 K): LiquidAppearance: heavy silvery white metalDensity: 13.546 g/cc (20  °C)Melting Point: 234.32 K (-38.83  °C or -37.894  °F)Boiling Point: 356.62 K (356.62  °C or 629.77  °F)Critical Point: 1750 K at 172 MPaHeat of Fusion: 2.29 kJ/molHeat of Vaporization: 59.11 kJ/molMolar Heat Capacity: 27.983 J/mol ·KSpecific Heat: 0.138 J/g ·K (at 20  °C) Mercury Atomic Data Oxidation States: 2 , 1Electronegativity: 2.00Electron Affinity: not stableAtomic Radius: 1.32 Ã…Atomic Volume: 14.8 cc/molIonic Radius: 1.10 Ã… (2e) 1.27 Ã… (1e)Covalent Radius: 1.32 Ã…Van der Waals Radius: 1.55 Ã…First Ionization Energy: 1007.065 kJ/molSecond Ionization Energy: 1809.755 kJ/molThird Ionization Energy: 3299.796 kJ/mol Mercury Nuclear Data Number of isotopes: There are 7 naturally occurring isotopes of mercury..Isotopes and % abundance: 196Hg (0.15), 198Hg (9.97), 199Hg (198.968), 200Hg (23.1), 201Hg (13.18), 202Hg (29.86) and 204Hg (6.87) Mercury Crystal Data Lattice Structure: RhombohedralLattice Constant: 2.990 Ã…Debye Temperature: 100.00 K Mercury Uses Mercury is amalgamated with gold to facilitate the recovery of gold from its ores. Mercury is used to make thermometers, diffusion pumps, barometers, mercury vapor lamps, mercury switches, pesticides, batteries, dental preparations, antifouling paints, pigments, and catalysts. Many of the salts and organic mercury compounds are important. Miscellaneous Mercury Facts Mercury compounds with the 2 oxidation states are known as mercuric in older texts. Example: HgCl2 was known as mercuric chloride.Mercury compounds with the 1 oxidation state are known as mercurous in older texts. Example: Hg2Cl2 was known as mercurous chloride.Mercury is rarely found free in nature. Mercury is harvested from cinnabar (mercury(I) sulfide - HgS). It is extracted by heating the ore and collecting the mercury vapor produced.Mercury is also known by the name quicksilver.Mercury is one of the few elements that is liquid at ordinary room temperatures.Mercury and its compounds are highly poisonous. Mercury is readily absorbed across unbroken skin or though the respiratory or gatroinstestinal tract. It acts as a cumulative poison.Mercury is very volatile in air. When room temperature air (20 °C) is saturated with mercury vapor, the concentration greatly exceeds the toxic limit. The concentration, and thus the danger, increases at higher temperatures.Early alchemists believ ed all metals contained varying amounts of mercury. Mercury was used in many experiments to transmute one metal into another. Chinese alchemists believed mercury promoted health and extended life and included it with several medicines.Mercury readily forms alloys with other metals, called amalgams. The term amalgam literally means alloy of mercury in Latin.An electrical discharge will cause mercury to combine with the noble gases argon, krypton, neon, and xenon.Mercury is one of the heavy metals. Many metals have a higher density than mercury, yet are not considered to be heavy metals. This is because heavy metals are both extremely dense and highly toxic. Sources Eisler, R. (2006). Mercury hazards to living organisms. CRC Press. ISBN 978-0-8493-9212-2.Greenwood, Norman N.; Earnshaw, Alan (1997). Chemistry of the Elements (2nd ed.). Butterworth-Heinemann. ISBN 0-08-037941-9.Lide, D. R., ed. (2005). CRC Handbook of Chemistry and Physics (86th ed.). Boca Raton (FL): CRC Press. ISBN 0-8493-0486-5.Norrby, L.J. (1991). Why is mercury liquid? Or, why do relativistic effects not get into chemistry textbooks?. Journal of Chemical Education. 68 (2): 110. doi:10.1021/ed068p110Weast, Robert (1984). CRC, Handbook of Chemistry and Physics. Boca Raton, Florida: Chemical Rubber Company Publishing. pp. E110. ISBN 0-8493-0464-4. Return to the Periodic Table

Prehistoric Life During the Silurian Period

Prehistoric Life During the Silurian Period The Silurian period only lasted 30 or so million years, but this period of geologic history witnessed at least three major innovations in prehistoric life: the appearance of the first land plants, the subsequent colonization of dry land by the first terrestrial invertebrates, and the evolution of jawed fish, a huge evolutionary adaptation over previous marine vertebrates. The Silurian was the third period of the Paleozoic Era (542-250 million years ago), preceded the Cambrian and Ordovician periods and succeeded by the Devonian, Carboniferous and Permian periods. Climate and Geography Experts disagree about the climate of the Silurian period; global sea and air temperatures may have exceeded 110 or 120 degrees Fahrenheit, or they might have been more moderate (only 80 or 90 degrees). During the first half of the Silurian, much of the earths continents were covered by glaciers (a holdover from the end of the preceding Ordovician period), with climatic conditions moderating by the start of the ensuing Devonian. The giant supercontinent of Gondwana (which was destined to break apart hundreds of millions of years later into Antarctica, Australia, Africa and South America) gradually drifted into the far southern hemisphere, while the smaller continent of Laurentia (the future North America) straddled the equator. Marine Life During the Silurian Period Invertebrates. The Silurian period followed the first major global extinction on earth, at the end of the Ordovician, during which 75 percent of sea-dwelling genera went extinct. Within a few million years, though, most forms of life had pretty much recovered, especially arthropods, cephalopods, and the tiny organisms known as graptolites. One major development was the spread of reef ecosystems, which thrived on the borders of the earths evolving continents and hosted a wide diversity of corals, crinoids, and other tiny, community-dwelling animals. Giant sea scorpions - such as the three-foot-long Eurypterus - were also prominent during the Silurian, and were by far the biggest arthropods of their day. Vertebrates. The big news for vertebrate animals during the Silurian period was the evolution of jawed fish like Birkenia and Andreolepis, which represented a major improvement over their predecessors of the Ordovician period (such as Astraspis and Arandaspis). The evolution of jaws, and their accompanying teeth, allowed the prehistoric fish of the Silurian period to pursue a wider variety of prey, as well as to defend themselves against predators, and was a major engine of subsequent vertebrate evolution as the prey of these fish evolved various defenses (like greater speed). The Silurian also marked the appearance of the first identified lobe-finned fish, Psarepolis, which was ancestral to the pioneering tetrapods of the ensuing Devonian period. Plant Life During the Silurian Period The Silurian is the first period for which we have conclusive evidence of terrestrial plants - tiny, fossilized spores from obscure genera like Cooksonia and Baragwanathia. These early plants were no more than a few inches high, and thus possessed only rudimentary internal water-transport mechanisms, a technique that took tens of millions of years of subsequent evolutionary history to develop. Some botanists speculate that these Silurian plants actually evolved from freshwater algae (which would have collected on the surfaces of small puddles and lakes) rather than ocean-dwelling predecessors. Terrestrial Life During the Silurian Period As a general rule, wherever you find terrestrial plants, youll also find some kinds of animals. Paleontologists have found direct fossil evidence of the first land-dwelling millipedes and scorpions of the Silurian period, and other, comparably primitive terrestrial arthropods were almost certainly present as well. However, large land-dwelling animals were a development for the future, as vertebrates gradually learned how to colonize dry land. Next: the Devonian Period

Organization Behaviour Research Paper Example | Topics and Well Written Essays - 2500 words

Organization Behaviour - Research Paper Example Correspondingly, studies have revealed that various factors are associated with the theory of OB, which makes it a multidimensional approach to contemporary management, constituting the perceptions of job satisfaction, organizational commitment and job attitudes among others. Among its various dimensions, this research paper will mainly discuss the topic of job attitudes with the focus on investigating the level of both job satisfaction and organizational commitment within a specific business organization, i.e. Kaiser Permanente Northwest. Notably, it is the employees involved in the operational process of any business organization, responsible for the determination of organizational culture. Hence, job attitude amid employees, determined by their job satisfaction degree, can be apparently observed as a crucial facet to enhance their organizational commitment and subsequently, outline the organizational culture (Saari and Judge 396-407). With this concern, the research paper intends to conduct an OB audit of an American healthcare organization, i.e. Kaiser Permanente Northwest. The outline of this research paper has accordingly been structured with a brief overview of this healthcare organization, followed by the analysis of data gathered, to conclude the findings as well as the results obtained from the interviewees. Subsequently, certain recommendations, based on the analysis about how the healthcare organization might address its weaknesses or deficiencies, with respect to the above stated topic and a solid conclusion have also been incorporated in the outline. Kaiser Permanente (KP) is a health care company and America’s leader in formulating effective nonprofit health plans. Established in the year 1945, KP was created to help provide Americans medical care during the situations of Great Depression as well as World War II when health care was unaffordable. As of December 31, 2013, KP has a network of 38 hospitals, approximately 190,000

Ecotourism and community development Assignment

Ecotourism and community development - Assignment Example Ecotourism involves travelling to natural places with the aim of conserving the environment and improving the livelihood of the inhabitants of the region Forsyth (2010). Edgell (2006) argues that as a trend, ecotourism emerged in 1980 s and it involved small-scale visits, however in the recent years people have become more aware of it leading to its grown popularity. In Thailand, ecotourism has several benefits that point towards the conservation of the natural environment especially the Thai’s mangrove forests. Sirinart Rajini mangrove-ecosystem learning centre is the first product of the government’s effort to promote ecotourism. Created from an abandoned shrimp farm the centre aims to provide the residents with practical knowledge on the importance of promoting ecotourism. Following the establishment of a shrimp farm in the Sirinart Rajini ecosystem, the natural mangrove forest and environment was greatly affected and therefore the government aims to restore it by pr omoting ecotourism (Thanomrak, 2011). The centre works with the local communities to promote environmental conservation through soil conservation and reforestation. The centre therefore aims at establishing a sustainable ecosystem that benefits people and other inhabitants of the environment. ... The definition also includes the desire to conserve the natural environment as the second objective of ecotourism. Ecotourism generally targets the creation of awareness in people on the need to conserve the deteriorating natural resources (Wood, 2002). Ecotourism also promote the development of the local communities through promotion of economic activities that are aimed at the conservation of the natural environment and resources. Through ecotourism programs, the government is also pushing its agenda of poverty eradication through the promotion of sustainable community development projects Neth (2008). Although ecotourism has massive and notable benefits, some scholars have pointed at some disadvantages on the activity that focus on the long-term developments. Promoting ecotourism has led into encroachment into the natural environment and this has caused ecological imbalance. The process has therefore led to the destruction of ecosystems that are of great biological importance for the future generations. The need to generate more revenue has accelerated the pace of destruction of the natural environment and therefore the country would do better without the activity. Ecotourism has also exposed native communities of the country to external influence and this has promoted cultural interference (Belanger, 2006). The activity has therefore weakened the culture of the Thai people that had been one of the strongest cultures of the world. Through promoting ecotourism, cultural and religious values that are of great importance to the people and the country are being eroded constantly. The government is therefore conscious of the long-term effect of the activity in the

History of Biological Warfare Essay Example for Free

History of Biological Warfare Essay Biological warfare, also called germ warfare is the use of bacteria, toxins, virus or harmful organism by the military as weapons of war against the enemy. This means that a small quantity of these microorganisms have the capability to kill millions of people if spread evenly and effectively. These biological weapons can also cause sickness to enemy soldiers and disrupt enemy’s logistics and supply lines. Although biological warfare as such has hitherto not taken place on a large scale, yet assuming and apprehending its probable occurrence, many nations have built their individual defensive strategies to be on the safe side. On the basis of this assumption and probability, much research for the purpose of defense against biological weapons has been conducted by the scientists, highly sensitive industries and the governments. But since carrying out germ-warfare against humanity or using harmful bacteria or organism against human beings was considered entirely inhumane, an international treaty banning biological weapons came into force in 1975. By virtue of this treaty, production, possession, and use of such weapons were completely prohibited. More than 150 nations signed this treaty. Deadly Forms of Warfare in History The origin of biological warfare is traced back in ancient times, when the Assyrians, in 6th century B. C poisoned enemy wells with poisonous herbs (eukaryotes or fungi) that cused the enemy lose sanity or consciousness. This was the starting point of biological warfare in human history. Thence onward this typical warfare was used by many in the past e. g. Solon of Athens poisoned the water supply of Phocaea with extremely poisonous herb Veratrum, during his city’s siege; the archers of Scythian, during 4th century B. C. poisoned the tips of arrows to cause infection into the wounds of enemy; the Spartans used sulfur during the Peloponnesian War in 400 B. C. In medieval times, soldiers used to throw dead bodies into the wells. During the Indian-French wars in1689 and 1763, blankets used by smallpox patients were given to Indians for carrying the disease to the latter. It was Germany, which, during World War I, used poisonous gas for the first time against Allied forces at Belgium and Ypres. The use of poisonous gas by Germany caused about 30 percent of casualties suffered by the US army. The use of poisonous gas proved so fatal and devastating in nature that many nations unanimously agreed to ban the use of gas and extremely harmful chemical substances in future wars. But again it was Iraq which breached the agreement and used chemical weapons against Iran in eight years long war (1980-1988). Iraq was also held responsible for using chemical weapons against the independence seeking Kurdish people. Relatively New Forms of Warfare Some of the new forms of warfare that have lately engaged nations in the design, technique and art of modern warfare include: 1. Chemical Warfare 2. Biological Warfare 3. Radiological Warfare 4. Mine Warfare 5. Guerrilla Warfare 6. Amphibious Warfare 7. Psychological warfare 8. Siege Warfare 9. Nuclear Warfare From the above forms of warfare, the chemical, radiological, and biological warfare are singled out as ones in which CBR weapons are used for mass killing; disabling millions of people instantly, transmitting fatal diseases into enemy rank and file; incapacitating the enemy physically, and destroying their food supplies. How do they Work? Chemical Warfare Chemical Warfare involves all those chemical substances which affect the nervous as well as the respiratory systems, besides affecting skin, eyes, and nose. The chemicals, which include gases, liquids, and powders, can be sprayed from airplanes, dropped as bombs, fired in the form of artillery shells, or spread over the area through land mines. But there are some colorless and odorless nerve agents which, if inhaled, can cause immediate death while some chemical agents can cause temporary blindness or confusion. The mustard gas also called ‘Blister Agent’ caused many casualties during World War I. But it is quite relieving to see the chemical agents not widely used in warfare since the end of World War I (1918). Radiological Warfare Radiological Warfare involves those substances that give off radiation, and which may damage the internal organs of a person and even cause death. Radiological warfare is extremely dangerous because the released radioactivity in the process renders the entire area unfit for human life. Mine Warfare Mine Warfare is the use of explosive devices called mines to kill enemy troops and destroy their ships, tanks, and other equipment. Some mines explode when a person steps on them or run over by a tank or jeep, while the naval mines are detonated by the passing of a ship. The two major kinds of mines are: 1. The Land Mines 2. The Naval Mines The main types of land mines are:1) antipersonnel mines, 2) antitank mines, 3) chemical mines, 4) controlled mines, and 5) nuclear mines. There chief four kinds of naval mines include: 1) acoustic mines, 2) contact mines, 3) magnetic mines, and 4) pressure mines Guerrilla warfare Guerrilla warfare is conducted by the fighter bands that employ the tactics of sudden raids, ambushes, and other attacks on small-scale. The term â€Å"Guerrilla† which means â€Å"Little War† in Spanish, was first used by the Portuguese and Spanish armies during the Peninsular War (1808-1814). Amphibious warfare Amphibious warfare is the mode of army operations by land air and sea forces with the objective of capturing a coastal area or a beach. Generally the amphibious operations are considered the most intricate form of modern warfare. During World War II (1939-1945), after Japanese had attacked Pearl Harbor and destroyed US naval installations in the Pacific Ocean, a common objective of United States amphibious warfare was to seize islands in order to build their advance on. These air and naval bases were captured for their operations against Japan. Antidotes for Biological Weapons The antidote for biological agents is a complete kit which contains medicines and treatments for nerve gas. It also contains injectors to fight anthrax, and antibiotics and drugs to reduce the effects of radiation exposure. Normally the kits are kept locked in military vans by the army. It is worthwhile noting that according to the briefing documents prepared by the Army Medical Department for the senior medical command in Iraq Millions of dollars worth of such kits are incinerated in Iraq each year. Army spokesman, Foster, D. said that the services policy is to issue the [kits] to each unit prior to deployment, and ensure all unused [kits are] turned in prior to the units redeployment for destruction. Also the vice president for strategic security programs at the Federation of American Scientists, Ivan Oelrich, said that sending the Antidote-kits is a rational policy just in case some terrorist gets hold of 10 gallons of nerve as† (Bob, 2007) Gas Mask Among other protective coverings such as injections of antidotes, gas masks too are used as one of the defensive measures against chemical agents. Gas mask protects a person from breathing poisonous gases and vapors into the lungs. Only air is allowed to enter the mask through the filter pads, which purifies and filters the air. The charcoal which is padded within the cheeks of mask purifies the air by trapping harmful gases and particles. Particulate filters can remove particles of smoke, dust, and even some harmful biological agents. The purifying materials are in the cheeks of present-day masks, which are often part of an entire protective suit. In World War I (1914-1918), masks were used to protect troops against gas attacks. Gas was not used in World War II (1939-1945), but armies had masks in case gas warfare began. During the Persian Gulf War of 1991 and the Iraq War, which began in 2003, gas masks were issued to troops and civilians in areas where it was feared Iraq would attack. (Lussier and Frances M, 2007)

The Effect of Age on Taste Essay -- Senses Aging Essays

The Effect of Age on Taste The sense of taste has to be one of the most important human senses. It gives an individual the ability to recognize consumables that are encountered on a regular basis such as a favorite steak platter or a favorite wine. However, when that individual reaches a particular age the sense of taste deteriorates, which can result in potentially dangerous conditions such as malnourishment or susceptibility to diseases. This problem of taste loss due to aging needs to be studied more because it can effect both the physical and mental health of many elderly people. When elderly individuals try to live life with a weakened ability to recognize certain food flavors or any other consumable item, their dietary needs can be greatly affected. A certain number of foods are not going to taste good enough to satisfy the appetites of the elderly, so they might resort to using unhealthy eating habits. For example, they could lose the motivation to eat certain foods such as vegetables or meats and increase the consumption of foods that are low in nutritional value such as candies or pastries. This shift can result in health problems such as a loss in bone mass, a weakened immune system, weak muscles, and high blood pressure. Elderly citizens need to acquire a specific amount of nutrients in order to maintain a healthy life style. Spence (1989) mentioned that diets which maintain adequate levels of vitamins and minerals and also consist of 50 to 55% carbohydrates, 12 to 15% proteins, and 25 to 35% fats are recommended for persons over the age of 50. In order for the elderly to live up to a healthy diet, they need to consume nutritious foods that will taste good to them. The problem with this situation is how to h... ...ews, 50 (12), 72-75. Miller, J. (1988). Human taste bud density across adult age groups. Journal of Gerontology, 43 (1), 26-30. Schieber, F. (1992). Aging and the senses. In J. E. Birren, R. B. Sloane, & G. D. Cohen (Eds.), Handbook of mental health and aging. San Diego: Academic Press Inc. Schiffman, S. (1977). Food recognition by the elderly. Journal of Gerontology, 32 (5), 586-592. Schiffman, S. (1994). Changes in taste and smell: Drug interactions and food preferences. Nutrition Reviews, 52 (8), 11-14. Schiffman, S. (1997). Taste and smell loss in normal aging and disease. Journal of the American Medical Association, 278 (16), 1357-1362. Spence, A. P. (1989). Biology of human aging. New Jersey: Prentice Hall. Spitzer, M. E. (1986). Taste acuity in institutionalized and non institutionalized elderly men. Psychological Sciences, 43 (3), 71-74.

Companies and the education Essay

It is no denying the fact that globalization is evil, in the real sense of the word, for countries like India, Pakistan and many other developing countries. Globalization is good among the developed countries- like America, Canada, Europe etc. because here the competition is on equal terms. Globalization is also fair among the developing countries, like India, Pakistan etc. But it cannot be said that globalization or competition is fair and on equal terms between developed countries on the one hand and the developing countries on the other hand. It does not make sense that Pakistan will be able to compete on equal level with America. The outcome of this competition can be forecasted easily i. e. all the benefits will definitely go in the pockets of the multinationals of the developed world and the developing ones will suffer greatly in this bargain. It can be said that globalization is a modern method of enslaving the third world countries. In the name of globalization the Western world is dictating the developing countries to open their markets and reduce expenses on social causes, the likes of education and health, while on the other hand the developed countries themselves are subsidizing their farmers, multinational companies and the education. This kind of globalization does not make any sense. But yes it can be called as Westernization. Globalization is the modern face of colonization. In globalization the poor and developing countries are to provide cheap raw materials for the developed world in return for expensive manufactured goods. Thus the developing countries will never be able to produce goods as cheap goods as the all-pervasive multinationals will be producing. They will just provide cheap labor. The supporters of globalization say that globalization has actually decreased the global poverty. They say that no doubt most countries have seen lower income growth but the world’s two largest countries china and India have experienced the opposite. They also say that it is only those countries that increasingly integrate them with the world economy that have managed to grow fastest and reduce poverty the most. Thus it is suggested by them that only those countries who open themselves very much to the world can be benefited in this bargain. Now let us check these arguments of the supporters of the globalization. â€Å"Economists agonize about capital flows but often overlooks the social disruptions, cultural clashes and political changes that globalization brings. † (Mott. 2004. p. 33) It is no doubt that exports and foreign investment played integral role in China’s development. China is able to buy the capital equipments and the other modern tools for its modernization by selling its home-made products in the length and breathe of the world. The managerial and technical expertise of china is also increased by the increase in foreign investment. Now take a close look and we discover that china’s economic policies violated almost all the rules and regulations according to which the supporters of globalization want to play their game. China joined the World Trade Organization only a year or two back and they also did not liberalize their trade policies to a great extent. Their economic policies are the most protected policies in the world. China opens its financial markets to the world just a little time back. Chinese know that the solutions to their problems must be the one suitable to the local conditions. Thus they developed and progress immensely not by following the hard and fast rules of globalization but by will, dedication and nicely built policies suitable to the local environment. On the other hand many countries that open themselves up to the world without taking care of the local demands and conditions suffer financially and functionally. For example, Latin America followed the principles of globalization with great zeal and gusto in the 1990sis suffering from increasing inequality, low economic growth rates, and heightened.