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    How Do Atoms Have Changed

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    As Chemistry Summary of how the atoms have changed throughout the years? One of the first founders of the idea of atoms was called Democritus‚ which was in 430 BC. He argued that there were an infinite number of different types of atoms. They were all different shape however they were made from the same stuff. He describes atoms as indivisible particles and also explained certain natural occurrences such as the existence of elements. Atomos (in ancient Greek) means “that which cannot be further

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    The History of the Atom Hypothesis according to Aristotle (350 BC): All matter consists of the elements earth‚ air‚ fire‚ and water. Experiment: A tree grows from the earth as water is added. The tree is then set on fire in an effort to form new elements. 1. What kind of results would be observed from this experiment? Fire‚ ash (earth)‚ smoke (air) 2. Would these observations support or reject the hypothesis? Explain. Support. No elements have been produced that are something other than

    Free Atom Electron Electric charge

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    Chemistry Report

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    Standardize a solution of potassium manganate(VII) by an iron (II) salt (ammonium iron (II) sulphate) Introduction Oxidation numbers describe the number of electrons the atom will gain or lose during a reaction. Each atom in an equation can be assigned an oxidation number according to certain rules. If the oxidation number of an atom increases as you go from the left side to the right side if an equation‚ oxidation has occurred (electrons have been lost); if the oxidation number decreases‚ reduction

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    REASONING BASED QUESTIONS OF ORGANIC CHEMISTRY 1. Chlorobenzene is less reactive than chloromethane. Ans. In chlorobenzene‚ each carbon atom of benzenering is sp2 hyridised and is electron withdrawing. Chlorine atom donates a lone pair of electron and acquire positive charge. The negative charge is delocalised on ortho and para position by resonance. C-Cl bond acquires partial double bond character and is 169 pm as compared to 17.0 pm in chloromethane where C atom is sp3 hybridised. So larger amount

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    Chemistry and Biotechnology

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    Elemental Analysis 1Professor‚ School of Chemical Engineering‚ Chemistry and Biotechnology‚ Mapua Institute of Technology; 2Student‚ CHM146L-B31‚ School of Chemical Engineering‚ Chemistry and Biotechnology‚ Mapua Institute of Technology [pic] ABSTRACT Elemental analysis of organic compounds determine the elements present in them but they do not give the actual structure or the functional groups present. Since all organic compounds contain hydrogen and carbon‚ most tests consist of only the

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    Sustainable Chemistry

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    Sustainable Chemistry    Terry Collins* Chemistry has an important role to play in achieving a sustainable civilization on Earth. The present economy remains utterly dependent on a massive inward flow of natural resources that includes vast amounts of nonrenewables. This is followed by a reverse flow of economically spent matter back to the ecosphere. Chemical sustainability problems are determined largely by these economy-ecosphere materials flows (see the figure‚ below)‚ which current chemistry education

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    Food Chemistry

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    Food Chemistry: Option F Food Groups: F.1 Food & Nutrients Food: any substance‚ whether processed‚ semi-processed or raw‚ which is intended for human consumption‚ and includes drinks‚ chewing gum and any substance which has been used in the manufacture‚ preparation or treatment of “food” but does not include cosmetics or tobacco or substances used only as drugs. Nutrients: any substance obtained from food and used by the body to provide energy‚ to regulate growth‚ and to maintain and repair

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    Organic Chemistry

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    * Introduction to Organic Chemistry Understand the basis of drawing organic structures Depicting 3-D structures in 2-D Most organic compounds have a three-dimensional structure. How do we represent structures on our two-dimensional page? For example‚ methane is a tetrahedral molecule: Bonds in the plane of the paper: Bonds coming towards the observer: (out of the page) Bonds going away

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    Gabby Dodgson 2A Oxygen Atom Essay A Day in the Life Being an oxygen atom isn’t as easy as it sounds‚ humans love us so much and those other atoms are always trying to attach themselves to us. Honestly‚ can they be anymore clingy? Really were the Michael Jordan’s of the element world. Todays the day I leave my home in the Tundra Biome‚ finally graduated from the periodic table and am on my way to the Tropics. I can’t wait‚ I’m so sick of this freezing weather and lack of any biotic diversity.

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    Chemistry Notes

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    Chemistry Notes Cracking: * 2 types of Cracking; Catalytic cracking and Steam/thermal cracking. * Catalytic cracking‚ using a catalyst called Zeolite (Aluminosilicate)‚ 500 degrees C‚ in the absence of air and at pressures just above atmospheric * Thermal cracking is done without a catalyst; steam is passed through very hot metal tubes at 700-1000 degrees C at just above atmospheric pressure. * This is used to break down longer chains of unsalable hydrocarbons into smaller salable

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