Metal Subgroups
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Promotion Effects and Mechanism of Alkali Metals and Alkaline Earth
Subscriber access provided by RES CENTER OF ECO ENVIR SCI Article Promotion Effects and Mechanism of Alkali Metals and Alkaline Earth Metals on Cobalt#Cerium Composite Oxide Catalysts for N2O Decomposition Li Xue, Hong He, Chang Liu, Changbin Zhang, and Bo Zhang Environ. Sci. Technol., 2009, 43 (3), 890-895 • DOI: 10.1021/es801867y • Publication Date (Web): 05 January 2009 Downloaded from http://pubs.acs.org on January 31, 2009 More About This Article Additional resources and features associated with this article are available within the HTML version: • Supporting Information • Access to high resolution figures • Links to articles and content related to this article • Copyright permission to reproduce figures and/or text from this article Environmental Science & Technology is published by the American Chemical Society. 1155 Sixteenth Street N.W., Washington, DC 20036 Environ. Sci. Technol. 2009, 43, 890–895 Promotion Effects and Mechanism such as Fe-ZSM-5 are more active in the selective catalytic reduction (SCR) of N2O by hydrocarbons than in the - ° of Alkali Metals and Alkaline Earth decomposition of N2O in a temperature range of 300 400 C (3). In recent years, it has been found that various mixed Metals on Cobalt-Cerium oxide catalysts, such as calcined hydrotalcite and spinel oxide, showed relatively high activities. Composite Oxide Catalysts for N2O One of the most active oxide catalysts is a mixed oxide containing cobalt spinel. Calcined hydrotalcites containing Decomposition cobalt, such as Co-Al-HT (9-12) and Co-Rh-Al-HT (9, 11), have been reported to be very efficient for the decomposition 2+ LI XUE, HONG HE,* CHANG LIU, of N2O. -
The Periodic Electronegativity Table
The Periodic Electronegativity Table Jan C. A. Boeyens Unit for Advanced Study, University of Pretoria, South Africa Reprint requests to J. C. A. Boeyens. E-mail: [email protected] Z. Naturforsch. 2008, 63b, 199 – 209; received October 16, 2007 The origins and development of the electronegativity concept as an empirical construct are briefly examined, emphasizing the confusion that exists over the appropriate units in which to express this quantity. It is shown how to relate the most reliable of the empirical scales to the theoretical definition of electronegativity in terms of the quantum potential and ionization radius of the atomic valence state. The theory reflects not only the periodicity of the empirical scales, but also accounts for the related thermochemical data and serves as a basis for the calculation of interatomic interaction within molecules. The intuitive theory that relates electronegativity to the average of ionization energy and electron affinity is elucidated for the first time and used to estimate the electron affinities of those elements for which no experimental measurement is possible. Key words: Valence State, Quantum Potential, Ionization Radius Introduction electronegative elements used to be distinguished tra- ditionally [1]. Electronegativity, apart from being the most useful This theoretical notion, in one form or the other, has theoretical concept that guides the practising chemist, survived into the present, where, as will be shown, it is also the most bothersome to quantify from first prin- provides a precise definition of electronegativity. Elec- ciples. In historical context the concept developed in a tronegativity scales that fail to reflect the periodicity of natural way from the early distinction between antag- the L-M curve will be considered inappropriate. -
Stable Isotopes of Cobalt Properties of Cobalt
Stable Isotopes of Cobalt Isotope Z(p) N(n) Atomic Mass Natural Abundance Nuclear Spin Co-59 27 32 58.93320 100.00% 7/2- Cobalt was discovered in 1735 by Georg Brandt. Its name derives from the German word kobald, meaning "goblin" or "evil spirit." Minerals containing cobalt were used by the early civilizations of Egypt and Mesopotamia for coloring glass deep blue. Cobalt oxide is used today to add a pink or blue color to glass. It is also an important trace element in soils and necessary for animal nutrition. The most important modern use of cobalt is in the manufacture of various wear-resistant and superalloys. Its alloys have shown high resistance to corrosion and oxidation at high temperatures. Radioactive Cobalt-60 is used in radiography and in the sterilization of food. A silvery-white, shining, hard, ductile, somewhat malleable metal, cobalt is also ferromagnetic, with permeability two-thirds that of iron. It has exceptional magnetic properties in alloys. It is attached by dilute hydrochloric and sulfuric acids. It corrodes readily in air, and it has unusual coordinating properties, especially the trivalent ion. It is noncombustible except in powder form. Cobalt occurs in two allotropic modifications over a wide range of temperatures: the crystalline close-packed- hexagonal form is known as the alpha form, which turns into the beta (or gamma) form above 417 ºC. In finely powdered form, cobalt ignites spontaneously in air. Reactions with acetylene and bromine pentafluoride proceed to incandescence and can become violent. The metal is moderately toxic by ingestion. Inhalation of dusts can damage lungs. -
An Alternate Graphical Representation of Periodic Table of Chemical Elements Mohd Abubakr1, Microsoft India (R&D) Pvt
An Alternate Graphical Representation of Periodic table of Chemical Elements Mohd Abubakr1, Microsoft India (R&D) Pvt. Ltd, Hyderabad, India. [email protected] Abstract Periodic table of chemical elements symbolizes an elegant graphical representation of symmetry at atomic level and provides an overview on arrangement of electrons. It started merely as tabular representation of chemical elements, later got strengthened with quantum mechanical description of atomic structure and recent studies have revealed that periodic table can be formulated using SO(4,2) SU(2) group. IUPAC, the governing body in Chemistry, doesn‟t approve any periodic table as a standard periodic table. The only specific recommendation provided by IUPAC is that the periodic table should follow the 1 to 18 group numbering. In this technical paper, we describe a new graphical representation of periodic table, referred as „Circular form of Periodic table‟. The advantages of circular form of periodic table over other representations are discussed along with a brief discussion on history of periodic tables. 1. Introduction The profoundness of inherent symmetry in nature can be seen at different depths of atomic scales. Periodic table symbolizes one such elegant symmetry existing within the atomic structure of chemical elements. This so called „symmetry‟ within the atomic structures has been widely studied from different prospects and over the last hundreds years more than 700 different graphical representations of Periodic tables have emerged [1]. Each graphical representation of chemical elements attempted to portray certain symmetries in form of columns, rows, spirals, dimensions etc. Out of all the graphical representations, the rectangular form of periodic table (also referred as Long form of periodic table or Modern periodic table) has gained wide acceptance. -
Cobalt Publications Rejected As Not Acceptable for Plants and Invertebrates
Interim Final Eco-SSL Guidance: Cobalt Cobalt Publications Rejected as Not Acceptable for Plants and Invertebrates Published literature that reported soil toxicity to terrestrial invertebrates and plants was identified, retrieved and screened. Published literature was deemed Acceptable if it met all 11 study acceptance criteria (Fig. 3.3 in section 3 “DERIVATION OF PLANT AND SOIL INVERTEBRATE ECO-SSLs” and ATTACHMENT J in Standard Operating Procedure #1: Plant and Soil Invertebrate Literature Search and Acquisition ). Each study was further screened through nine specific study evaluation criteria (Table 3.2 Summary of Nine Study Evaluation Criteria for Plant and Soil Invertebrate Eco-SSLs, also in section 3 and ATTACHMENT A in Standard Operating Procedure #2: Plant and Soil Invertebrate Literature Evaluation and Data Extraction, Eco-SSL Derivation, Quality Assurance Review, and Technical Write-up.) Publications identified as Not Acceptable did not meet one or more of these criteria. All Not Acceptable publications have been assigned one or more keywords categorizing the reasons for rejection ( Table 1. Literature Rejection Categories in Standard Operating Procedure #4: Wildlife TRV Literature Review, Data Extraction and Coding). No Dose Abdel-Sabour, M. F., El Naggr, H. A., and Suliman, S. M. 1994. Use of Inorganic and Organic Compounds as Decontaminants for Cobalt T-60 and Cesium-134 by Clover Plant Grown on INSHAS Sandy Soil. Govt Reports Announcements & Index (GRA&I) 15, 17 p. No Control Adams, S. N. and Honeysett, J. L. 1964. Some Effects of Soil Waterlogging on the Cobalt and Copper Status of Pasture Plants Grown in Pots. Aust.J.Agric.Res. 15, 357-367 OM, pH Adams, S. -
The Development of the Periodic Table and Its Consequences Citation: J
Firenze University Press www.fupress.com/substantia The Development of the Periodic Table and its Consequences Citation: J. Emsley (2019) The Devel- opment of the Periodic Table and its Consequences. Substantia 3(2) Suppl. 5: 15-27. doi: 10.13128/Substantia-297 John Emsley Copyright: © 2019 J. Emsley. This is Alameda Lodge, 23a Alameda Road, Ampthill, MK45 2LA, UK an open access, peer-reviewed article E-mail: [email protected] published by Firenze University Press (http://www.fupress.com/substantia) and distributed under the terms of the Abstract. Chemistry is fortunate among the sciences in having an icon that is instant- Creative Commons Attribution License, ly recognisable around the world: the periodic table. The United Nations has deemed which permits unrestricted use, distri- 2019 to be the International Year of the Periodic Table, in commemoration of the 150th bution, and reproduction in any medi- anniversary of the first paper in which it appeared. That had been written by a Russian um, provided the original author and chemist, Dmitri Mendeleev, and was published in May 1869. Since then, there have source are credited. been many versions of the table, but one format has come to be the most widely used Data Availability Statement: All rel- and is to be seen everywhere. The route to this preferred form of the table makes an evant data are within the paper and its interesting story. Supporting Information files. Keywords. Periodic table, Mendeleev, Newlands, Deming, Seaborg. Competing Interests: The Author(s) declare(s) no conflict of interest. INTRODUCTION There are hundreds of periodic tables but the one that is widely repro- duced has the approval of the International Union of Pure and Applied Chemistry (IUPAC) and is shown in Fig.1. -
Development of a Solvent Extraction Process for Group Actinide Recovery from Used Nuclear Fuel
THESIS FOR THE DEGREE OF DOCTOR OF PHILOSOPHY Development of a Solvent Extraction Process for Group Actinide Recovery from Used Nuclear Fuel EMMA H. K. ANEHEIM Department of Chemical and Biological Engineering CHALMERS UNIVERSITY OF TECHNOLOGY Gothenburg, Sweden, 2012 Development of a Solvent Extraction Process for Group Actinide Recovery from Used Nuclear Fuel EMMA H. K. ANEHEIM ISBN 978-91-7385-751-2 © EMMA H. K. ANEHEIM, 2012. Doktorsavhandlingar vid Chalmers tekniska högskola Ny serie Nr 3432 ISSN 0346-718X Department of Chemical and Biological Engineering Chalmers University of Technology SE-412 96 Gothenburg Sweden Telephone + 46 (0)31-772 1000 Cover: Radiotoxicity as a function of time for the once through fuel cycle (left) compared to one P&T cycle using the GANEX process (right) (efficiencies: partitioning from Table 5.5.4, transmutation: 99.9%). Calculations performed using RadTox [HOL12]. Chalmers Reproservice Gothenburg, Sweden 2012 Development of a Solvent Extraction Process for Group Actinide Recovery from Used Nuclear Fuel EMMA H. K. ANEHEIM Department of Chemical and Biological Engineering Chalmers University of Technology Abstract When uranium is used as fuel in nuclear reactors it both undergoes neutron induced fission as well as neutron capture. Through successive neutron capture and beta decay transuranic elements such as neptunium, plutonium, americium and curium are produced in substantial amounts. These radioactive elements are mostly long-lived and contribute to a large portion of the long term radiotoxicity of the used nuclear fuel. This radiotoxicity is what makes it necessary to isolate the used fuel for more than 100,000 years in a final repository in order to avoid harm to the biosphere. -
The Periodic Table of Elements
The Periodic Table of Elements 1 2 6 Atomic Number = Number of Protons = Number of Electrons HYDROGENH HELIUMHe 1 Chemical Symbol NON-METALS 4 3 4 C 5 6 7 8 9 10 Li Be CARBON Chemical Name B C N O F Ne LITHIUM BERYLLIUM = Number of Protons + Number of Neutrons* BORON CARBON NITROGEN OXYGEN FLUORINE NEON 7 9 12 Atomic Weight 11 12 14 16 19 20 11 12 13 14 15 16 17 18 SODIUMNa MAGNESIUMMg ALUMINUMAl SILICONSi PHOSPHORUSP SULFURS CHLORINECl ARGONAr 23 24 METALS 27 28 31 32 35 40 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 POTASSIUMK CALCIUMCa SCANDIUMSc TITANIUMTi VANADIUMV CHROMIUMCr MANGANESEMn FeIRON COBALTCo NICKELNi CuCOPPER ZnZINC GALLIUMGa GERMANIUMGe ARSENICAs SELENIUMSe BROMINEBr KRYPTONKr 39 40 45 48 51 52 55 56 59 59 64 65 70 73 75 79 80 84 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 RUBIDIUMRb STRONTIUMSr YTTRIUMY ZIRCONIUMZr NIOBIUMNb MOLYBDENUMMo TECHNETIUMTc RUTHENIUMRu RHODIUMRh PALLADIUMPd AgSILVER CADMIUMCd INDIUMIn SnTIN ANTIMONYSb TELLURIUMTe IODINEI XeXENON 85 88 89 91 93 96 98 101 103 106 108 112 115 119 122 128 127 131 55 56 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 CESIUMCs BARIUMBa HAFNIUMHf TANTALUMTa TUNGSTENW RHENIUMRe OSMIUMOs IRIDIUMIr PLATINUMPt AuGOLD MERCURYHg THALLIUMTl PbLEAD BISMUTHBi POLONIUMPo ASTATINEAt RnRADON 133 137 178 181 184 186 190 192 195 197 201 204 207 209 209 210 222 87 88 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 FRANCIUMFr RADIUMRa RUTHERFORDIUMRf DUBNIUMDb SEABORGIUMSg BOHRIUMBh HASSIUMHs MEITNERIUMMt DARMSTADTIUMDs ROENTGENIUMRg COPERNICIUMCn NIHONIUMNh -
The Group 1A and Group 2A Elements
Cotton chapter 10,11 Group 1A Group 1A Qualitative alkali metal analysis Alkali Metals y The group 1A elements with their ns1 valence electron configurations are very active metals. They lose their valence electrons very readily. They have low ionization energies and react with nonmetals to form ionic solids. 2Na(s) +Cl2(g) Æ 2NaCl(s) y The expected trend in reducing ability, Cs>Rb>K>Na>Li y Alkali metals all react vigorously with water to release hydrogen gas. + ‐ 2M(s) +2H2O(l) Æ 2M (aq) +2OH(aq) +H2(g) y Observed reducing abilities: Li>K>Na First ionization energy Soda production Properties and Trends in Group 1A y The Group 1A metals exhibit regular trends for a number of properties. y Irregular trends suggest that factors are working against each other in determining a property (such as the density “discrepancy” between sodium and potassium). y The alkali metals have two notable physical properties: they are all soft and have low melting points. y When freshly cut, the alkali metals are bright and shiny—typical metallic properties. The metals quickly tarnish, however, as they react with oxygen in the air. Alkali Metal Oxides In the presence of ample oxygen, 4Li + O2 → 2Li2O(regularoxide) 2Na + O2 → Na2O2 (peroxide) K+O2 → KO2 (superoxide) Rb + O2 → RbO2 (superoxide) Cs + O2 → CsO2 (superoxide) The oxides of Group 1A Direct reaction of the alkali metals with O2 gives : Li ‐> oxide, peroxide (trace) Na ‐> peroxide , oxide (trace) K,Rb,Cs ‐> superoxide Diagonal Relationships: The Special Case of Lithium In some of its properties, lithium and its compounds resemble magnesium and its compounds. -
TEK 8.5C: Periodic Table
Name: Teacher: Pd. Date: TEK 8.5C: Periodic Table TEK 8.5C: Interpret the arrangement of the Periodic Table, including groups and periods, to explain how properties are used to classify elements. Elements and the Periodic Table An element is a substance that cannot be separated into simpler substances by physical or chemical means. An element is already in its simplest form. The smallest piece of an element that still has the properties of that element is called an atom. An element is a pure substance, containing only one kind of atom. The Periodic Table of Elements is a list of all the elements that have been discovered and named, with each element listed in its own element square. Elements are represented on the Periodic Table by a one or two letter symbol, and its name, atomic number and atomic mass. The Periodic Table & Atomic Structure The elements are listed on the Periodic Table in atomic number order, starting at the upper left corner and then moving from the left to right and top to bottom, just as the words of a paragraph are read. The element’s atomic number is based on the number of protons in each atom of that element. In electrically neutral atoms, the atomic number also represents the number of electrons in each atom of that element. For example, the atomic number for neon (Ne) is 10, which means that each atom of neon has 10 protons and 10 electrons. Magnesium (Mg) has an atomic number of 12, which means it has 12 protons and 12 electrons. -
Where Is Water on the Periodic Table
Where Is Water On The Periodic Table Grum Jess regrown some tirls and risk his creepies so ambrosially! Roderigo is edaphic: she libel ahold and budges her barm. Corrugate and percipient Ford never digitized lickerishly when Janos literalising his ultrafilter. Unsubscribe from rivers from three particles in marah was it is where water on the periodic table The periodic tables is where compounds is a question yourself. Periodic table organized his element does not the water where is on oxygen and silicon does the universe and the sight of concentration and. In the marine environment. The table is where it is generally halogens are. An appreciation of water resources, data for gym, make tungsten gets very sophisticated pieces of oxo anions. Tcp connection time is table is on the water periodic. In the 9th century BC a Spartan lawgiver invented a drinking cup that could go mud stick missing its turn Later on the posture of medicine Hippocrates developed a device called the Hippocrates Sleeve a cloth bag weight was used to strain boiled rain water eliminating hoarseness and even smell. His law that is an apartment building large version of a ratio of where water was given element in open a pond would accumulate at an outer shells need. On their properties? Free 2-day shipping Buy Chemistry Elements Pet Mat the Food make Water Periodic Table of Elements in Green Shades Education Themed Non-Slip Rubber. The wall of the cell is the plasma membrane that controls the rate and type of ions and molecules passing into and out of the cell. -
Preparation of Barium Strontium Titanate Powder from Citrate
APPLIED ORGANOMETALLIC CHEMISTRY Appl. Organometal. Chem. 13, 383–397 (1999) Preparation of Barium Strontium Titanate Powder from Citrate Precursor Chen-Feng Kao* and Wein-Duo Yang Department of Chemical Engineering, National Cheng Kung University, Tainan, 70101, Taiwan TiCl4 or titanium isopropoxide reacted with INTRODUCTION citric acid to form a titanyl citrate precipitate. Barium strontium citrate solutions were then BaTiO3 is ferroelectric and piezoelectric and has added to the titanyl citrate reaction to form gels. extensive applications as an electronic material. It These gels were dried and calcined to (Ba,Sr)- can be used as a capacitor, thermistor, transducer, TiO3 powders. The gels and powders were accelerometer or degausser of colour television. characterized by DSC/TGA, IR, SEM and BaTiO3 doped with strontium retains its original XRD analyses. These results showed that, at characteristics but has a lower Curie temperature 500 °C, the gels decomposed to Ba,Sr carbonate for positive temperature coefficient devices under and TiO2, followed by the formation of (Ba,Sr)- various conditions. TiO3. The onset of perovskite formation oc- Besides solid-state reactions, chemical reactions curred at 600 °C, and was nearly complete at have also been used to prepare BaTiO3 powder. 1 1000 °C. Traces of SrCO3 were still present. Among them the hydrolysis of metal alkoxide , The cation ratios of the titanate powder oxalate precipitation in ethanol2, and alcoholic prepared in the pH range 5–6 were closest to dehydration of citrate solution3 are among the more the original stoichiometry. Only 0.1 mol% of the attractive methods. In 1956 Clabaugh et al.4 free cations remained in solution.