English Proficiency This test is designed to assess the test takers’ general proficiency in the use of English language as a means of self-expression in real life situations and specifically to test the test takers’ knowledge of basic grammar‚ their vocabulary‚ their ability to read fast and comprehend‚ and also their ability to apply the elements of effective writing. 1. Grammar 1. Agreement‚ Time and Tense‚ Parallel construction‚ Relative pronouns 2. Determiners‚ Prepositions‚ Modals
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Chemistry S-20 Week 1 Alkenes: Isomers and Nomenclature 1. There are 6 unique alkene isomers of the hydrocarbon C5H10. Draw each of these isomers‚ and provide a systematic name for each. 1-pentene (E)-2-pentene (Z)-2-pentene 2-methyl-1-butene 2-methyl-2-butene 3-methyl-1-butene 2. For the three alkenes above which are various isomers of pentene‚ rank them in order of stability. Explain your ranking. most stable (more subst. double bond) less stable (cis alkene is
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An ion is an atom or molecule in which the total number of electrons is not equal to the total number of protons‚ giving it a net positive or negative electrical charge. The name was given by physicist Michael Faraday for the substances that allow a current to pass ("go") between electrodes in a solution‚ when an electric field is applied. It is from Greek ιον‚ meaning "going." The word ion also is responsible for electrical current being symbolized by the letter i in chemistry and physics. An anion
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WJEC CBAC AS/A LEVEL GCE in Chemistry REVISION AID UNIT 1 AS UNIT CH1 – Controlling and Using Chemical Changes (in order to make things‚ produce energy and solve environmental problems) Preamble This unit begins with some important fundamental ideas about atoms and the use of the mole concept in calculations. Three key principles governing chemical change are then studied‚ viz. the position of equilibrium between reactants and products‚ the energy changes associated with a
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fluorine end is slightly negative. This causes hydrogen bonding between other hydrogen fluoride molecules. KCl – potassium chloride is a metal halide salt. The bonding between potassium and chloride is an ionic bond. The potassium becomes a cation and the chloride an anion. The potassium end of the molecule becomes slightly positive and the other end slightly negative. Na – sodium contains metallic bonding. It has a high melting due to the bonding and has strong bonds. Each sodium atom is being touched
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Edexel IGCSE Chemistry Revision Notes IGCSE Chemistry Triple Award Revision Guide Topic Introduction to chemistry Atomic Structure Structure and Bonding – Ionic Bonding Structure and Bonding – Covalent and Metallic Bonding Organic Chemistry - Alkanes Organic Chemistry – Alkenes / Addition Polymerisation Organic Chemistry – Alcohols / Condensation Polymerisation Calculations Periodic Table Reactivity Series and Metal Extraction Electrolysis Energetics Acids‚ Bases‚ Salts and Neutralisation
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recommended for this topic (a) Reaction classes Only three reaction classes occur in (organic) chemistry‚ defined as: (i) Heterolytic – here one partner donates or departs with both electrons while the other (partner) supplies a vacant orbital. The reaction-energy diagram (profile) tends to have at least one intermediate. These reactions involve a “two-electron push”: Examples: (ii) Homolytic – here each partner supplies one electron as a radical (a species with a single unpaired electron)
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Part I Multiple choice or short answer questions 1) (2 points) Identify a solid a. Definite volume and no definite shape b. no definite volume and no definite shape c. definite volume and definite shape 2) (2 points) A substance composed of two or more elements in a fixed‚ definite proportion is a. A solution. b. A heterogeneous mixture. c. An alloy. d. A homogeneous mixture. e. A compound. 3) (2 points) Read the water
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and Violets are blue Answer human eye can view only the color that is reflected‚ the remaining color in visible spectrum are being absorbed by the plant pigments for energy use. Molecule or Molecular ion | Valence shell Electron pairs | Bonding Electron pairs | Nonbonding Electron pairs | VSEPR Formula | Approx. Bond Angle | Geometric Shape | BrCl3 | 5 | 3 | 2 | AX3E2 | <90o | T-shaped | IF4- | 6 | 4 | 2 | AX4E2 | 90o | Square planar | CO2 | 2 | 2 | 0 | AX2 | 180o | Linear
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Works Cited………………………………………………………………………………………………………….9 Word Count: 1.782 Year 12 Chemistry HL DUBAI INTERNATIONAL ACADEMY Aim The aim of this investigation is to determine the formula of the complex ion formed from copper (II) ions and ammonia through colorimetry. Results Raw Data Table 1: The Effect of CuSO4:NH3 Volume Ratio (cm³) (±0.05) on Absorbance (±0.01) Independent Variable: Volume (cm³) (±0.05) CuSO4 NH3 0.00 0.00 1.00 9.00 1.50 8.50 2.00 8.00 2.50 7.50 3.00
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