Assessment 1) Describe the difference between ionic and covalent bond. Ionic bonds have electrostatic forces that hold cations and anions together‚ and are electronic neutral. Covalent bonds are bonds that don’t give or take any electrons. In stead they share the elctrons 50) Which of these compounds contain elements that do not follow the octet rule? Explain. a) NF3: 5 + (7*3) = 26 b) PCl2F3: 5 + (7*2) + (7*3) = 40 c) SF4: 6 + (7 *4) = 24 d) SCl2: 6 + (7*2) = 20 The answer is “d”
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Soil erosion Soil erosion occurs when soil is removed through the action of wind and water at a greater rate than it is formed SOIL The soil covering the surface of the earth has taken millions of years to form and we must learn to respect it. Soil is formed at a rate of only 1 cm every 100 to 400 years and it takes 3 000 to 12 000 years to build enough soil to form productive land. This means that soil is a nonrenewable resource and once destroyed it is gone forever. If we disregard this‚ a
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MANAGEMENT REVIEW SHEET Coastal Erosion Subject Review The following reports and articles contain the information needed to complete this worksheet: “Evaluation of Erosion Hazards” prepared by the H. John Heinz III Center for Science‚ Economics and the Environment (summary report) http://www.heinzctr.org/NEW_WEB/PDF/erosnsum.pdf “Mapping Coastal Change Hazards” U.S.G.S. website beginning at http://coastal.er.usgs.gov/hurricanes/mappingchange/ “Coastal Erosion: Where’s the Beach?” Bridge Data
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Coastal Erosion Coastal erosion is a naturally occurring phenomenon resulting from the continuous action of wind and water. Both act to remove small pieces of land from one location and deposit them elsewhere. Weather events such as hurricanes and nor’easters speed the erosion process‚ as do tidal waves. Currently‚ rising sea levels resulting from melting polar ice decrease available land as well. While erosion has always been a factor of coastal living‚ increasing populations along the worlds
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Metallic Bonding Metallic Bonding Why do metals conduct electricity? Metals conduct electricity. The delocalised electrons are free to move throughout the structure in 3-dimensions. They can cross grain boundaries. Even though the pattern may be disrupted at the boundary‚ as long as atoms are touching each other‚ the metallic bond is still present. Liquid metals also conduct electricity‚ showing that although the metal atoms may be free to move‚ the delocalisation remains in force until the
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Class 6 The actual test paper has 50 questions. Time allowed : 60 minutes. There are 2 sections: 15 questions in section I and 35 in section II. Syllabus Section – I (Mental Ability) : Knowing our Numbers‚ Whole Numbers‚ Playing with Numbers‚ Basic Geometrical Ideas‚ Understanding Elementary Shapes‚ Integers‚ Fractions‚ Decimals‚ Data Handling‚ Mensuration‚ Algebra‚ Ratio and Proportion‚ Symmetry‚ Practical Geometry‚ Logical Reasoning. Section – II (Science) : Motion and Measurement of Distances
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Chemical bonds are what make up the world. In bonds‚ elements are held together and form compounds that may have new physical and chemical properties. There are two main kinds of bonds‚ they ionic and covalent. In bonding the goal of the atoms involved is to reach a level of stability with less energy. In order to reach the epitome of stability‚ as in the case of noble gases‚ an atom strives to complete its outer shell. Either losing or gaining electrons may do this‚ which concludes in an ionic bond
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Soil Erosion Erosion is a natural process by which rock and soil are broken loose from the earth’s surface at one location and moved to another. Soil erosion forms and changes land by wearing down mountains filling valleys‚ and making rivers appear and disappear. Erosion is usually a slow and gradual process that occurs over the course of thousands or millions of years. However the rate of erosion can be speeded up by such human activities as mining. How erosion occurs? Ero0sion begins with
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Beach erosion longstanding challenge for southeastern NC There is a major environmental concern in the southeastern region North Carolina; it is beach erosion. However do not worry‚ the article states “The good news is that we do have alternatives to help control erosion‚ but the bad news is that these alternatives can also have negative consequences.”. A method that is able to help control erosion is beach nourishment‚ although it is not a cure for beach erosion‚ but rather a treatment to help
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The soils ability to grab and hold important nutrient ions until they are absorbed by the roots is just as important as the supply of those initial ions. Soil erosion is the most damaging force against top soil. Soil erosion happens anytime soil is bared and exposed to the elements. Wind and water have a dramatic effect on soil erosion because both events have a tendency to remove the humus particles and carry them away from the soil. The removal can be a slow and gradual process when soil is gradually
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