Dobereiner noticed that the atomic weight of strontium fell midway between the weights of calcium and barium‚ elements possessing similar chemical properties. In 1829‚ after discovering the halogen triad composed of chlorine‚ bromine‚ and iodine and the alkali metal triad of lithium‚ sodium and potassium he proposed that nature contained triads of elements the middle element had properties that were an average of the other two members when ordered by the atomic weight (the Law of Triads). This new idea
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Introductory Chemistry‚ 2e (Tro) Chapter 9 – Electrons in Atoms and the Periodic Table True/False Questions 1) When the elements are arranged in order of increasing number of protons‚ certain sets of properties recur periodically. 5) A particle of light is called a packet. 9) Ultraviolet light produces suntans and sunburns. 13) Electrons behave like particles and we can describe their exact paths. 17) The ground state is when an electron in an atom is excited into the lowest possible vacant orbital
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The Apparel Industry: Issues and Solutions 1 Please note: This report focuses on environmental impacts and solutions associated with apparel‚ a second report will present the equally complex social responsibility (SR) issues associated with this industry’s life cycle including fair trade‚ fair labor and animal well-being issues. Published by Labeling Ecologically Approved Fabrics (LEAF) Special thanks to: Coral Rose‚ Founder Eco-Innovations Sustainable Textile Strategies Dr. Gwendolyn Hustvedt-Professor
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Therefore‚ chemical treatments are considered in modifying the fiber surface properties. In this paper‚ the different chemical modifications on natural fibers for use in natural fiber-reinforced composites are reviewed. Chemical treatments including alkali‚ silane‚ acetylation‚ benzoylation‚ acrylation‚ maleated coupling agents‚ isocyanates‚ permanganate and others are discussed. The chemical treatment of fiber aimed at improving the adhesion between the fiber surface and the polymer matrix may not
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CHAPTER 1 The Problem and Its background 1.1 INTRODUCTION The growing interest in the past to produce green materials that can reduce the problem involving waste materials by non-fibrous materials led to the development of natural fiber reinforced thermoplastic composites. Water Hyacinth (Eichhornia crassipes) also known as “water lily” is an aquatic plant which is found floating freely in the surface of fresh waters. Its rate of proliferation under certain circumstances is extremely
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A fermenter is an apparatus that maintains optimal conditions for the growth of microorganisms. The main function of the fermenter is to provide a controlled environment for the growth of a pure culture or of a defined mixture of microorganisms or animal cell to obtain the desired product. Different parts of fermenter:- 1) Fermenter Vessel: A suitable vessel is used to carry out the whole fermentation process. The vessel is capable of being operated aseptically and meet the containment
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faster than the lava when it is moving! The layers of a cone volcano are usually alternated between lava and ash. A shield volcano usually has a wide cone and gentle slopes. The lava that is ejected during an eruption is thin due to it being basic (alkali). At first thought‚ you would think a volcano to be a curse. This is because it spews out gallons and gallons of hot lava that can easily scorch you to death. Also a cone volcano has the capability of emitting something called a pyroclastic flow
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Application From:- VIntukumar.C.Parmar‚ Parmarstreet‚ At&Post–TA-Vagra
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The objective of the deicer lab was to successfully conduct experiments to determine the usefulness of magnesium chloride as a deicer. To find how successful magnesium chloride is as a deicer‚ experiments were conducted to determine the freezing point depression‚ enthalpy of dissolution‚ the impact on the surrounding environment‚ and also the expenses of using magnesium chloride as a deicer. For magnesium chloride to be determined as a good deicer‚ the reaction with water needs to be exothermic so
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Ocean County College Department of Chemistry Identification of Metallic Ions Purpose: The purpose of this lab exercise was to perform and observe the flame tests of some alkali and alkaline earth metal ions. When electrons in metallic ions are grounded‚ their configuration is stable. In other words‚ the loosely bound electrons in the valence shell of the atom are satisfied at their “low” energy state. They do not require to be balanced by emitting any type of radiation or receiving any
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