Extraction of metals The History of Metals. Metals have been used by people for many thousands of years. Gold and silver‚ found as native metal‚ were used both as jewellery and as a status symbol - nothing new there. These metals were known in the Stone Age‚ but gold and silver are too soft to be used as tools. The first really useful metal to be discovered was bronze. This began the Bronze Age. Bronze was used extensively for tools and weapons in Asia and Africa from 4‚500 B.C. (6‚500 years
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Tony Nguyen Honors Chemistry Period 7 9/17/13 The Density of Metals Lab BACKROUND: Density is a constant relationship between the mass and volume of a specific type of matter. Measurements of both mass and volume can be obtained for a metal sample. The relationship can be shown graphically by plotting the volume of a sample on the horizontal x-axis and the mass of the sample along the vertical y-axis. Plotting the values for several samples‚ a linear relationship can be seen for a density (slope=density)
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Schools have Metal Detectors? Have you ever felt violated‚ disrespected and dishonored to the point of no return? Many students around the world feel such a way every day. According to a 2002 National School Board Association report‚ 10.1 percent of school districts nationwide implement the use of metal detectors. Are metal detectors even effective? Why should students be forced to cooperate with a violation of their rights? High Schools around the world should not employ the use of metal detectors
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A metal is defined as an opaque shiny element which possesses properties such as malleability and ductility. Malleable meaning that they can be hammered into shapes and ductile meaning they can be drawn into wires. They are also very strong and posses high tensile strength and are good conductors of heat and electricity. Metals are shiny‚ and also have high densities. Metals are a very important and significant part of chemistry. However‚ their importance is not just limited to chemistry; they are
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Transition Metals 1a) The d-orbitals of a free transition metal atom or ion are degenerate (all have the same energy.) However‚ when transition metals form coordination complexes‚ the d-orbitals of the metal interact with the electron cloud of the ligands in such a manner that the d-orbitals become non-degenerate (not all having the same energy.) The way in which the orbitals are split into different energy levels is dependent on the geometry of the complex. Crystal field theory can be used to predict
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when finding truth and wisdom. The other prisoners reaction to the escapee returning represents that people are sccared of knowing philosophical truths and do not trust philosophers. Plato’s allegory of the cave relates to the quote because in The Matrix Neo can be seen as the escaped prisoner of the cave who has obtained knowledge of the outside world which is the true form of the world. When he asks “I cannot go back‚ can I ?” It means that there is no turning back for him even if he wants to‚ as
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Susan Professor Dr. Tyler Veak Philosophy 201- B12 LUO 4 February 2013 Plato‚ Descartes‚ and The Matrix Consider this‚ Is what we believe to be real and true real and true? In the movie The Matrix‚ Neo is a computer programer by day and hacker by night. He senses that something is wrong with the world but insists what he know he feels. When he dreams‚ he isn’t sure if it was real or just a dream just as Descartes believes he cannot trust his senses to tell him whether or not he is still
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Alkali Metals Introduction Alkali metals refer to six elements belonging to the Group IA of the long form of the Modern Periodic Table‚ viz. Lithium (Li)‚ Sodium (Na)‚ Potassium (K)‚ Rubidium (Rb)‚ Cesium (Cs) and Francium (Fr). Fr is a radioactive element. These elements are called so because they form strongly alkaline oxides and hydroxides. Electronic Configuration of Alkali Metals Each of the alkali metals has one electron in their outermost (valence) shell‚ which is just outside an inert
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EXTRACTION OF METALS SUMMARY Most metals exist in compounds in rocks in the Earth’s crust. Many of these ores contain oxides or sulphides of the metals. The compounds need to be reduced to produce the metals as elements. Metals are very useful to us because of their special properties. Reduction means removal of oxygen or gain of electrons. Carbon is a good chemical reducing agent because it readily combines with oxygen‚ but it is only useful for the metals below it in the Reactivity
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Resources‚ Conservation and Recycling 21 (1997) 145–173 Metals recycling: economic and environmental implications Robert U. Ayres * INSEAD‚ Boule6ard de Constance‚ F-77305‚ Fontainebleau‚ France Received 17 July 1997; accepted 27 July 1997 Abstract We are in a period of economic transition. The ‘cowboy economy’ of the past is obsolescent‚ if not obsolete. Environmental services are no longer free goods‚ and this fact is driving major changes. Recycling is the wave of the (immediate) future
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