Applications of Silicon Silicon is one of man’s most useful elements. In the form of sand and clay it is used to make concrete and brick; it is a useful refractory material for high-temperature work‚ and in the form of silicates it is used in making enamels‚ pottery‚ etc. Silica‚ as sand‚ is a principal ingredient of glass‚ one of the most inexpensive of materials with excellent mechanical‚ optical‚ thermal and electrical properties. Hyperpure silicon can be doped with boron‚ gallium‚ phosphorus
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CHEMISTRY UNIT 2 STRUCTURE OF ATOM The rich diversity of chemical behaviour of different elements can be traced to the differences in the internal structure of atoms of these elements. After studying this unit you will be able to • know about the discovery of electron‚ proton and neutron and their characteristics; • describe Thomson‚ Rutherford and Bohr atomic models; • understand the important features of the quantum mechanical model of atom; • understand nature
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2) B) 4 liters C) 6 x 1023 atoms D) 2 moles Which sample of O2 contains a total of 3.01 x 1023 molecules at STP? A) 16.0 grams B) 32.0 grams B) 6.02 x 1023 C) 2.00 moles D) 1.00 mole D) 1.20 x 1024 What is the total number of atoms contained in 2.00 moles of nickel? A) 118 C) 58.9 C) 1 liter of neon D) 1 gram of neon 3) 4) What quantity is represented by the symbol Ne? A) 1 mole of neon B) 1 atomic mass unit of neon 5) How many moles of hydrogen atoms are present in one mole of
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Electron Arrangement Purpose: The purpose of this lab is to write electron configurations‚ orbital filling diagrams‚ and electron- dot diagram for ten elements. Hypothesis: If the amount of electron is know them the configuration of the element is know. Equipment: Paper‚ Pencils Procedure: (IV) Independent Variable - Configuration of electron (DV) Dependent Variable – Multiple Energy Level (CM) Control Method – S‚P‚D‚F Orbital (CMI/C)Constant - S‚P‚D‚F Orbital 1. Prepare a table
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may approach those of metals. The physical properties of semiconductors are studied in solid-state physics. (Encarta 2) Silicon is the raw material most often used in integrated circuit (IC) fabrication. It is the second most abundant substance on the earth. It is extracted from rocks and common beach sand and put through an exhaustive purification process. In this form‚ silicon is the purist industrial substance that man produces‚ with impurities comprising less than one part in a billion. That is
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Silicon dioxide (SiO2) is one of the most common oxides on the surface of earth. Like most oxides‚ it adopts a polymeric structure. Оксидите се хемиски соединенија што содржат најмалку еден атом на кислород и еден атом од друг хемиски елемент во својата формула. An oxide /ˈɒksaɪd/ is a chemical compound that contains at least one oxygenatom and one other element[1] in its chemical formula. Metal oxides typically contain an anion of oxygen in the oxidation state of −2. Most of the Earth’s crustconsists
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FREE ELECTRON THEORY Classical free electron theory of metals This theory was developed by Drude and Lorentz and hence is also known as Drude-Lorentz theory. According to this theory‚ a metal consists of electrons which are free to move about in the crystal like molecules of a gas in a container. Mutual repulsion between electrons is ignored and hence potential energy is taken as zero. Therefore the total energy of the electron is equal to its kinetic energy. Drift velocity If no electric
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The History of the Atom The History of the Atom Democritus first proposed an atomic model. He said that all matter could be divided into smaller and smaller pieces until a single indivisible particle was reached. He called this particle an atom after the Greek word ‘atomos’ meaning not cuttable. He believed that different atoms are of different sizes‚ have regular geometric shapes and are always in motion. He also said that there is empty space between atoms. Aristotle severely criticized Democritus’
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Introduction to Electron Microscopy Prof. David Muller‚ dm24@cornell.edu Rm 274 Clark Hall‚ 255-4065 Ernst Ruska and Max Knoll built the first electron microscope in 1931 (Nobel Prize to Ruska in 1986) T4 Bacteriophage Electron Microscopy bridges the 1 nm – 1 μm gap David Muller 2008 between x-ray diffraction and optical microscopy Tools of the Trade AFM MFM Scanned Probe Microscope (includes Atomic Force Microscope) Transmission Electron Microscope Scanning Electron Microscope
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PROCEEDINGS OF THE IEEE‚ VOL. 70‚ NO. 5‚ MAY 1982 Silicon as a Mechanical Material KURT E. PETERSEN‚ MEMBER‚ IEEE Abstract-Single-crystal silicon is being increasingly employed in a variety of new commercial products not because of its well-established electronic properties‚ but rather because of its excellent mechanical properties. In addition‚ recent trends in the engineering literature indicate a growing interest in the use of silicon as a mechanical material with the ultimate goal of
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