List of Platinum Group Metals or PGMs

The platinum group metals or PGMs are a set of six transition metals that share similar properties. They may be considered a subset of the precious metals. The platinum group metals are clustered together on the periodic table, plus these metals tend to be found together in minerals. The list of PGMs is: Iridium  (Ir)Osmium  (Os)Palladium  (Pd)Platinum  (Pt)Rhodium  (Rh)Ruthenium  (Ru) Alternate Names: The platinum group metals are also known as: PGMs, platinum group, platinum metals, platinoids, platinum group elements or PGEs, platinides, platidises, platinum family Key Takeaways: Platinum Group Metals The platinum group metals or PGMs are a set of six precious metals that are clustered together on the periodic table around the element platinum.The elements share certain desirable properties with platinum. All are noble metals and transition metals in the d-block of the periodic table.The platinum group metals are widely used as catalysts, corrosion-resistant materials, and fine jewelry. Properties of the Platinum Group Metals The six PGMs share similar properties, including: Extremely high density (densest element is a PGM)Highly resistant to wear or tarnishResist corrosion or chemical attackCatalytic propertiesStable electrical propertiesStable at high temperatures Uses of PGMs Several of the platinum group metals are used in jewelry. In particular, platinum, rhodium, and iridium are popular. Because of the price of these metals, they are often used as coatings over softer, more reactive metals, such as silver.PGMs are important catalysts. Platinum catalysts are important in the petrochemical industry. Platinum or platinum-rhodium alloy are used to catalyze partial oxidation of ammonia to produce nitric oxide, an important raw material in chemical production. PGMS are also used as catalysts for organic chemical reactions. The automotive industry uses platinum, palladium, and rhodium in catalytic converters to treat exhaust emissions.Platinum group metals are used as alloying additives.PGMs may be used to make crucibles used to grow single crystals, particularly of oxides.Platinum group metal alloys are used to make electrical contacts, electrodes, thermocouples, and circuits.Iridium and platinum are used in medical implants and pacemakers. Sources of Platinum Group Metals Platinum gets its name from platina, meaning little silver, because the Spaniards considered it an unwanted impurity in silver mining operations in Colombia. For the most part, PGMs are found together in ores. Ultramafic and mafic igneous rocks contain high levels of platinum group metals, the granites contain a low percentage of the metals. The richest deposits include mafic layered intrusions, such as Bushveld Complex. Platinum metals are found in the Ural Mountains, North and South America, Ontario, and other places. Platinum metals are also produced as a by-product of nickel mining and processing. Additionally, the light platinum group metals (ruthenium, rhodium, palladium) form as fission products in nuclear reactors. Extraction Platinum metal extraction processes are typically trade secrets. First, the sample is dissolved in acid. Aqua regia is most often used for this purpose. This produces a solution of metal complexes. Basically, isolation uses the different solubilities and reactivities of the different elements in various solvents. While recovering noble metals from reactors is expensive, the escalating price of the metals has made spent nuclear fuel a viable source of the elements. History Platinum and its alloys occur in native form and were known by pre-Columbian Americans. Despite its early use, platinum does not appear in literature until the 16th century. In 1557, Italian Julius Caesar Scalinger wrote of a mysterious metal found in Central America that was unknown to Europeans. Fun Fact Iron, nickel, and cobalt are three transition metals located above the platinum group metals on the periodic table. They are the only transition metals that are ferromagnetic! Sources Kolarik, Zdenek; Renard, Edouard V. (2005). Potential Applications of Fission Platinoids in Industry. Platinum Metals Review. 49 (2): 79. doi:10.1595/147106705X35263Renner, H.; Schlamp, G.; Kleinwà ¤chter, I.; Drost, E.; Là ¼schow, H. M.; Tews, P.; Panster, P.; Diehl, M.; et al. (2002). Platinum group metals and compounds. Ullmanns Encyclopedia of Industrial Chemistry. Wiley. doi:10.1002/14356007.a21_075Weeks, M. E. (1968). Discovery of the Elements (7 ed.). Journal of Chemical Education. pp. 385–407. ISBN 0-8486-8579-2.Woods, Ian (2004). The Elements: Platinum. Benchmark Books. ISBN 978-0-7614-1550-3.Xiao, Z.; Laplante, A. R. (2004). Characterizing and recovering the platinum group minerals—a review. Minerals Engineering. 17 (9–10): 961–979. doi:10.1016/j.mineng.2004.04.001

The Immorality Of Having Children By Stuart Rachels

The paper, â€Å"The Immorality of Having Children†, by Stuart Rachels provides insight as to why it is wrong to raise children by supporting the Famine Relief Argument. Rachels argues that the cost of raising a child today, over two-hundred thousand, is so staggering that it would be better spent on donations towards famine relief projects. Throughout the paper, Rachels provides substantial arguments that emphasize the point that having children is the biggest decision that someone will ever make in their life rather than what to believe or whether to get married, and the decision should not be taken lightly. All the arguments presented are persuasive, but the argument is flawed overall because it never takes into account the importance of†¦show more content†¦Rather, Rachels opposes both the idea parenthood as well as accusing parents of their misjudgments.(Rachels, 572) This shows the awareness that Rachels has in objectively challenging the current stance that cou ples must have a child together. Altogether, Rachels has provided a strong paper that initially seems very convincing, but when taking a deeper look, one finds that there are several flaws in his argument. One of the major opponents to Rachels argument is Peter Singer. Singer writes about how it seems unfair for somebody to donate more than another person who may be in a similar situation. (Singer, 233) For example, if someone was considering having a child and were financially secure enough to provide for the child, Rachels would argue that the money they would spend on the child would be better used if it were donated to the famine relief charities. On the other hand, if an individual or couple were not planning on having a child, but rather wanted to not have children, they too would be required to give the same amount of money to the famine relief charities, but why would they be required to give the money away if they were not planning on having a child? So the initial ly strong argument provided by Rachels is weakened because there was little to no consideration given towards the population who may not want to have children.

The Awakening Essay Research Paper The central free essay sample

The Awakening Essay, Research Paper The cardinal narration of Kate Chopin? s novel The Awakening can be said to concern Edna Pontellier? s battle to specify herself as an active topic, and to discontinue to be simply the inactive object of forces beyond her control. But the precise nature of this battle, every bit good as its emotional and psychological dimensions, is less easy articulated. One textual opposite number to this complexness is the on-going interplay between active and inactive voice which analogues, and non infrequently undermines, the open narrative. The relationship between formal grammatical forms and obvious narrative significance shapes our apprehension of Edna? s altering consciousness and serves as an index to its alterations. The verb? awaken, ? from which the novels rubric and cardinal metaphor derive, officially complicates in a similar manner the active and inactive elements of Edna? s experience. The first portion of the book establishes contradiction and dichotomies presumptively to parallel what the narrative Tells about Edna. We will write a custom essay sample on The Awakening Essay Research Paper The central or any similar topic specifically for you Do Not WasteYour Time HIRE WRITER Only 13.90 / page She is continually baffled by her behaviour and feelings, and fluctuates between evident ego cognition and evident ego misrepresentation. Her perceptio Ns are hedged in modals and conditional constructions, negatives, and comparative clauses. Any sense of steering consciousness is undercut by verbal signals of uncertainty and vacillation. The caged birds that open the fresh set up instantly the sense of constrained potency that marks the first chapters. When Edna does see her first? breath of freedom? it is compared to wine and being rummy, images of delusory euphory that suggest merely an illusive loss of restraint. Edna? s complicated life falls off the dark Edna learns to swim, an event that is a exultant jubilation of the integrity of emotion and will. The eventide begins with the household amusements at which Mademoiselle Reisz is asked to play the piano. Edna? s out of the blue passionate response to the music transcends the solid domestic ambiance of the eventide. To her ain amazement the heathen and poetic images are absent and in their topographic point? the really passions Chopin, Kate. The Awakening: Complete, Authoritative Text with Biographical and Historical Contexts, Critical History, and Essaies from Five Contemporary Theoretical Critical Perspectives. Ed. Nancy A. Walker. Boston: St. Martin # 8217 ; s Press, 1993.