PHYSICAL SCIENCE I. HISTORICAL BACKGROUND A. Babylonians They recorded eclipses and they were able to predict future eclipses. They named the twelve divisions of the Zodiacs‚ divided the northern sky into constellation and gave their present names. Their priest recorded planetary motions especially those of Venus‚ geometry and mathematics were highly developed by these people. There were evidences of multiplication tables and tables of square and cubes. They created standards for measuring length
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Lesson 03.01: History of the Periodic Table Explain how scientific observations led to the development of‚ and changes to‚ the periodic table. Russian chemist Dmitri Mendeleev set out to organize the 63 known elements according to their properties. Mendeleev wrote the name‚ mass‚ and chemical properties of each element on a separate card and arranged the cards by various properties‚ looking for trends and patterns. When he arranged the elements by increasing atomic mass‚ Mendeleev noticed that similar
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acid in the reaction loses a –OH hydroxyl group and the alcohol loses a single hydrogen to allow bonding to occur between the carbon and oxygen atoms. Esters are polar molecules‚ or molecules that are separated in polarity by differences in electronegativity and each individual atom’s pull on electrons. Basically‚ one part of the molecule is slightly positive and the other slightly negative. Whilst esters have dipole-dipole interactions and dispersion forces at work‚ they are not hydrogen-bond
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GRADE 11 CHEMISTRY (30S) Final Practice Examination Answer Key GRADE 11 CHEMISTRY (30S) Final Practice Examination Answer Key IInstructions The final examination will be weighted as follows Modules 1–3 Modules 4–6 The format of the examination will be as follows: Part A: Fill-in-the-Blanks Part B: Multiple Choice Part C: Short Answer Total Marks Include units with all answers as required. Useful Information You will need the following in order to complete this examination: n n n n 15–20% 80–85%
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Chapter 4 Carbon and the Molecular Diversity of Life Lecture Outline Overview: Carbon – The Backbone of Biological Molecules * Although cells are 70–95% water‚ the rest consists mostly of carbon-based compounds. * Carbon is unparalleled in its ability to form large‚ complex‚ and diverse molecules. * Carbon accounts for the diversity of biological molecules and has made possible the great diversity of living things. * Proteins‚ DNA‚ carbohydrates‚ and other molecules that
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1993 - 2(b) Marking Scheme (i) Diamond is a giant structure with covalent bonds/ giant covalent structure/ consist of a large number of covalent bond ∴ melting requires supply of a large amount of energy. Melting of tetrachloromethane involves the breaking of weak van der Waals forces between molecules/ intermolecular forces. 1+1 1 1 (ii) There are mobile electrons in solid sodium but the ions in solid sodium chloride are not free to move/ solid sodium chloride has no mobile
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As the world continues to modernize and reach new plateaus of technological and engineering successes‚ our urban areas are developing. More and more people are being packed into the densely populated cities that are popping up over both already developed and still-developing countries. With the rise of antibiotic-resistant bacteria and increases in contact with strangers met on the streets and in metro stations‚ the state of hygiene of a single individual is now more than ever having a direct impact
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CHAPTER 1 INTRODUCTION: THEMES IN THE STUDY OF LIFE OUTLINE I. Life’s Hierarchical Order A. The living world is a hierarchy‚ with each level of biological structure building on the level below it B. Each level of biological structure has emergent properties C. Cells are an organism’s basic units of structure and function D. The continuity of life is based on heritable information in the form of DNA E. Structure and function are correlated at all levels of biological organization F. Organisms are
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TERMPAPER TOPIC:- imperfection in solid’s NAME:-MILAN RAJAWAT Regd. No.:-11004886 Section:-M2R16 Roll No.:-B16 Subjet:-MEC208 INTRODUCTION For a crystalline solid we have tacitly assumed that perfect order exists throughout the material on an atomic scale. However‚ such an idealized solid does not exist; all contain large numbers of various defects or imperfections. As a matter of fact‚ many of the properties of materials are profoundly sensitive to
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Kull Key Chemistry 105 Practice Test 3 Spring 2007 Student: ________________________ The actual test will have 15 multiple choice‚ select 12 for grading‚ and 5 or 6 workout problems. There are no work-out problems here‚ bur the types of required computations are seen in the multiple choice problems here. I will place an updated equation sheet on the web by Wednesday morning‚ as well as post the answer key. 1 Who proposed a model that successfully explained the photoelectric effect? A
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