Molecular Geometry and Bonding Theory

Total Page:16

File Type:pdf, Size:1020Kb

Molecular Geometry and Bonding Theory Molecular Geometry and Bonding Theory Molecular Geometry and the VSEPR Theory Molecular Shapes for Steric Number 5 & 6 Page [1 of 3] Okay, let’s keep going and look at steric number 5, which it turns out is the most complicated of all of the possibilities. The reason is that steric number 5 is dictated by something called the “trigonal bi-pyramid,” and the trigonal bi- pyramid is characterized as having three that are at the corners of an equilateral triangle, and I’m going to hold that flat, and then there’s one at the north pole and one at the south pole, and you can see that the three that are in the plane, and then the one at the north pole are at the vertices of a pyramid. And then if we take the three in the plane and consider the one at the south pole, we have another pyramid, and so these are sort of back-to-back pyramids, hence the name, trigonal bi-pyramids. Now, one thing that makes that trigonal bi-pyramid really complicated is the fact that in the trigonal bi-pyramid all of the positions are not equivalent, whereas in the idealized tetrahedral geometry, for instance, all of the positions are exactly equivalent. That is to say that the trigonal bi-pyramid has something more in common with something like a lemon, which is not perfectly spherical or not as highly symmetric compared to a bocce ball, which you can see is very highly symmetric. The trigonal bi-pyramid is of lower symmetry. When we look at steric number 6, steric number 6 is build on the octahedron and once again will have that very high symmetry where very atom position is equivalent to every other atom position. So we have a distinction, and that distinction we’re going to label axial, for the two that are at the north pole at the south pole, and I’ve put these in yellow to remind you that there is this distinction, and then the three that are in the triangular plane, we’re going to call these equatorial. So we have axial and we have equatorial. Now, the bond angles in the trigonal bi-pyramid, there are three different bond angles. There is the 90-degree bond angle between the north pole and any of the balls on the equatorial plane, or for that matter, the south pole and any of the balls on the equatorial plane—that’s 90 degrees. And then from the north pole to the south pole, of course, that’s 180 degrees. And then the third bond angle is from one equatorial atom to another equatorial atom. That’s going to be 120 degrees. So there are three different bond angles in the trigonal bi-pyramid. Now, the molecule that has the idealized trigonal bi-pyramidal geometry, or an example would be something like phosphorous pentachloride, . And if you look at this picture here, I’ve labeled the chlorines that are equatorial, of which there are three. The way we draw this, a solid wedge is drawn to indicate that this one is coming out towards you. So it’s not in the plane, but it’s coming out towards you. And then the dashed line, that chlorine atom is going into the plane away from you, whereas these three chlorines, where we draw with just a single line, these are done to indicate that these three are in the plane. And so it’s possible, for instance, if we set it up like this, you can see that the north pole and the south pole, and one of the atoms in the equatorial plane are all in the same plane with the phosphorus atom, and then there’s one atom going towards you and one atom going away from you. So that’s the way we indicate it when we have a model for which we need to express three-dimensional geometry. So that’s the idealized trigonal bi-pyramid, but what happens if we have a lone pair? Why is this a problem? The problem is we have to decide should the lone pair live in an equatorial position or should the lone pair live in an axial position, because that’s going to give rise to two different predictions about geometry. Now, the rules—and I’m just going to list them off now and then show you how they work—are that rule 1—eliminate any structure that has lone pair/lone pair interaction at 90 degrees. Now, that rule is not going to be important for steric number 5, but it’s going to be very important for steric number 6. And then the second rule is of the remaining structures, choose the one with the fewest lone pair/bond pair interactions at 90 degrees. So again, the magic angle is 90 degrees. That’s what we need to focus on. So let’s consider a model of sulfur tetrafluoride, , and if we think about what the Lewis Dot structure for looks like it’s going to have single bonds between sulfur and each of the four fluorines, and then there’s going to be a lone pair. And that lone pair on sulfur we’re just going to indicate with this cloud where there’s the lone pair there. Now, you don’t see the lone pair, so when we’re describing the shape of the molecule, we’re just going to focus on the relative positions of the nuclei, just like before. But we can ask does that lone pair live or prefer to live in an equatorial position or does it prefer to live in an axial position. And so now we have to think about our rules. Since we only have one lone pair in each of these two structures, we don’t have to worry about the lone pair/lone pair interactions right now. We only have to worry about Molecular Geometry and Bonding Theory Molecular Geometry and the VSEPR Theory Molecular Shapes for Steric Number 5 & 6 Page [2 of 3] lone pair/bond pair interactions. I just realized I misspoke before. We are going to have to worry about rule 1 later on, but we don’t have to worry about rule 1 here. So let’s count the lone pair/bond pair interactions at 90 degrees. For this possible structure we have one to that fluorine, and we have one to that fluorine for a total of two. Whereas, for this structure we have one to that fluorine, and one to that fluorine, and one to the fluorine in the back, so we have a total of three. And recall that rule 2 says that we want to minimize the number of lone pair/bond pair interactions. Why do we want to do this? Well, it turns out, again, that lone pairs sort of seem to take up more space. And you’ll recall that electrons, being negatively charged, repel each other. And so what we’re basically saying is that we’re trying to minimize the coulomb repulsions, or the repulsions of electrons for each other by minimizing these lone pair/bond pair interactions, where again, lone pairs seem to be bigger. They have a greater physical extent, and so they’re the thing that we need to focus on most. So given that, this structure has fewer lone pair/bond pair interactions, this is going to be the preferred geometry for sulfur tetrafluoride, and if we go back to our trigonal bi-pyramidal structure, remember, lone pairs just represent the absence of an atom, and so what we’ve got is we’ve got something that looks like this. It’s still built on the same model, but there’s a lone pair out here that affects the geometry. So this is most definitely—so sulfur tetrafluoride is most definitely not a tetrahedral molecule. Right? What is it? Well, we describe this geometry as being a see-saw. Why is it a see-saw? Well, you can see that if we put it on its side it looks a little like a see-saw. Now, what are the bond angles? Just as before, since the lone pair appears to take up a little more space, you might imagine that the north pole to sulfur, the south pole angle is going to be a little bit less than 180 degrees, but not much, and similarly the equatorial fluorine to sulfur to fluorine, that bond angle might be a little bit less than 120, but pretty close to the idealized bond angles for the trigonal bi-pyramid. Okay. What happens if we have steric number 5 and two lone pairs? If we have steric number 5 and two lone pairs, then what we have to do is we have to consider rule number 1, and I’ll remind you that rule number 1 says avoid lone pair/lone pair interactions at 90 degrees. So chlorine trifluoride is an example of a molecule that has steric number 5 and two lone pairs. And you can convince yourself from a Lewis dot structure that that should be true. First of all, rule 1 says throw out any structures that have lone pair/lone pair interactions at 90 degrees. So let’s look at our possibilities. Why do we have three possibilities? Well, if you think about it, the three possibilities where two lone pairs are having both lone pairs equatorial, that’s this one, having both lone pairs axial, that’s the middle one, and then the third one is having one lone pair equatorial and one lone pair axial, and you can convince yourself that there really are only three possibilities.
Recommended publications
  • Chemistry of the Noble Gases*
    CHEMISTRY OF THE NOBLE GASES* By Professor K. K. GREE~woon , :.\I.Sc., sc.D .. r".lU.C. University of N ewca.stle 1tpon Tyne The inert gases, or noble gases as they are elements were unsuccessful, and for over now more appropriately called, are a remark­ 60 years they epitomized chemical inertness. able group of elements. The lightest, helium, Indeed, their electron configuration, s2p6, was recognized in the gases of the sun before became known as 'the stable octet,' and this it was isolated on ea.rth as its name (i]A.tos) fotmed the basis of the fit·st electronic theory implies. The first inert gas was isolated in of valency in 1916. Despite this, many 1895 by Ramsay and Rayleigh; it was named people felt that it should be possible to induce argon (apy6s, inert) and occurs to the extent the inert gases to form compounds, and many of 0·93% in the earth's atmosphere. The of the early experiments directed to this end other gases were all isolated before the turn have recently been reviewed.l of the century and were named neon (v€ov, There were several reasons why chemists new), krypton (KpVn'TOV, hidden), xenon believed that the inert gases might form ~€vov, stmnger) and radon (radioactive chemical compounds under the correct con­ emanation). Though they occur much less ditions. For example, the ionization poten­ abundantly than argon they cannot strictly tial of xenon is actually lower than those of be called rare gases; this can be illustrated hydrogen, nitrogen, oxygen, fl uorine and by calculating the volumes occupied a.t s.t.p.
    [Show full text]
  • The Noble Gases
    INTERCHAPTER K The Noble Gases When an electric discharge is passed through a noble gas, light is emitted as electronically excited noble-gas atoms decay to lower energy levels. The tubes contain helium, neon, argon, krypton, and xenon. University Science Books, ©2011. All rights reserved. www.uscibooks.com Title General Chemistry - 4th ed Author McQuarrie/Gallogy Artist George Kelvin Figure # fig. K2 (965) Date 09/02/09 Check if revision Approved K. THE NOBLE GASES K1 2 0 Nitrogen and He Air P Mg(ClO ) NaOH 4 4 2 noble gases 4.002602 1s2 O removal H O removal CO removal 10 0 2 2 2 Ne Figure K.1 A schematic illustration of the removal of O2(g), H2O(g), and CO2(g) from air. First the oxygen is removed by allowing the air to pass over phosphorus, P (s) + 5 O (g) → P O (s). 20.1797 4 2 4 10 2s22p6 The residual air is passed through anhydrous magnesium perchlorate to remove the water vapor, Mg(ClO ) (s) + 6 H O(g) → Mg(ClO ) ∙6 H O(s), and then through sodium hydroxide to remove 18 0 4 2 2 4 2 2 the carbon dioxide, NaOH(s) + CO2(g) → NaHCO3(s). The gas that remains is primarily nitrogen Ar with about 1% noble gases. 39.948 3s23p6 36 0 The Group 18 elements—helium, K-1. The Noble Gases Were Kr neon, argon, krypton, xenon, and Not Discovered until 1893 83.798 radon—are called the noble gases 2 6 4s 4p and are noteworthy for their rela- In 1893, the English physicist Lord Rayleigh noticed 54 0 tive lack of chemical reactivity.
    [Show full text]
  • 00419717.Pdf
    APPROVED FOR PUBLIC RELEASE APPROVED FOR PUBLIC RELEASE APPROVED FOR PUBLIC RELEASE ~ ,—- UNWMFIED — PUBUCLYREI-EMABLF . ,$5 ~ .~16f3 This Document Consists of 18 Pages /“ @ LQS ALAMOS SCIENTIFIC LABORATORY Contribution from Chemistry-MetallurgyDivision E. R. Jette, Division Leader J. F, Lemons, Group Leader Plutonium~‘=Hexaf uor e: Preparation and Properties w A. E. Flor November 9, 1950 — ‘1” Chemistry-Tranwrs.nicElements “-+ - ,- —. 1 Y– -t APPROVED FOR PUBLIC RELEASE — APPROVED FOR PUBLIC RELEASE LA-I.M8 UNCLASSIFIED Los tiSDIOS 1-20 STANDARD DISTRIBUTION Argonne,I?ationslLaboratory 21-30 Atomic Energy Commission, Washington 31-32 Brookhaven National Laboratory 33-36 Carbide and Carbon Cheticals Division (K-25 Plant) 37-38 Carbide and Carbon Chemicsl.sDivision (Y-12 Plant) General.Electric Company, Richland Z-45 Hanford Operations Office 46 Iowa State College 47 Kellex Corporation 4.$ Knolls Atomic Power Laboratory g-;; Mound Laboratory Navel Radiological Defense Laboratory 56- NEPA Project 57 New York Operations Office 58-59 Oak Ridge National Laboratory 60-65 Patent Branch, Washington 66 Technical Information Division, ORE 6741 UCLA Medical Research Laboratory (Warren) University of California Radiatio nLaboratory %85 University of Rochester 86-87 2 APPROVED FOR PUBLIC RELEASE — APPROVED FOR PUBLIC RELEASE Introduction It is the purpose of this paper to present the results of experi- mental investigations on the chemistry of plutonium hernfluoride con- ducted at this laboratory subsequent to the preparation of report LAMS 1118(1). A more satisfactory apparatus for the preparation is des- cribed. More reliable values for the vapor pressure have been obtained and the related physical constants have been calculated. The rate of decomposition of the compound as a result of the associated alpha radiation has been determined and a preliminary observation on the thermal stability is reported.
    [Show full text]
  • The Elements.Pdf
    A Periodic Table of the Elements at Los Alamos National Laboratory Los Alamos National Laboratory's Chemistry Division Presents Periodic Table of the Elements A Resource for Elementary, Middle School, and High School Students Click an element for more information: Group** Period 1 18 IA VIIIA 1A 8A 1 2 13 14 15 16 17 2 1 H IIA IIIA IVA VA VIAVIIA He 1.008 2A 3A 4A 5A 6A 7A 4.003 3 4 5 6 7 8 9 10 2 Li Be B C N O F Ne 6.941 9.012 10.81 12.01 14.01 16.00 19.00 20.18 11 12 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 3 Na Mg IIIB IVB VB VIB VIIB ------- VIII IB IIB Al Si P S Cl Ar 22.99 24.31 3B 4B 5B 6B 7B ------- 1B 2B 26.98 28.09 30.97 32.07 35.45 39.95 ------- 8 ------- 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 4 K Ca Sc Ti V Cr Mn Fe Co Ni Cu Zn Ga Ge As Se Br Kr 39.10 40.08 44.96 47.88 50.94 52.00 54.94 55.85 58.47 58.69 63.55 65.39 69.72 72.59 74.92 78.96 79.90 83.80 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 5 Rb Sr Y Zr NbMo Tc Ru Rh PdAgCd In Sn Sb Te I Xe 85.47 87.62 88.91 91.22 92.91 95.94 (98) 101.1 102.9 106.4 107.9 112.4 114.8 118.7 121.8 127.6 126.9 131.3 55 56 57 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 6 Cs Ba La* Hf Ta W Re Os Ir Pt AuHg Tl Pb Bi Po At Rn 132.9 137.3 138.9 178.5 180.9 183.9 186.2 190.2 190.2 195.1 197.0 200.5 204.4 207.2 209.0 (210) (210) (222) 87 88 89 104 105 106 107 108 109 110 111 112 114 116 118 7 Fr Ra Ac~RfDb Sg Bh Hs Mt --- --- --- --- --- --- (223) (226) (227) (257) (260) (263) (262) (265) (266) () () () () () () http://pearl1.lanl.gov/periodic/ (1 of 3) [5/17/2001 4:06:20 PM] A Periodic Table of the Elements at Los Alamos National Laboratory 58 59 60 61 62 63 64 65 66 67 68 69 70 71 Lanthanide Series* Ce Pr NdPmSm Eu Gd TbDyHo Er TmYbLu 140.1 140.9 144.2 (147) 150.4 152.0 157.3 158.9 162.5 164.9 167.3 168.9 173.0 175.0 90 91 92 93 94 95 96 97 98 99 100 101 102 103 Actinide Series~ Th Pa U Np Pu AmCmBk Cf Es FmMdNo Lr 232.0 (231) (238) (237) (242) (243) (247) (247) (249) (254) (253) (256) (254) (257) ** Groups are noted by 3 notation conventions.
    [Show full text]
  • Information to Users
    INFORMATION TO USERS This manuscript has been reproduced from the microfilm master. UMI films the text directly from the original or copy submitted. Thus, some thesis and dissertation copies are in typewriter free, while others may be from any type of computer printer. The quality of this reproduction is dependent upon the quality of the copy submitted. Broken or indistinct print, colored or poor quality illustrations and photographs, print bleedthrough, substandard margins, and improper alignment can adversely affect reproduction. In the unlikely event that the author did not send UMI a complete manuscript and there are missing pages, these will be noted. Also, if unauthorized copyright material had to be removed, a note will indicate the deletion. Oversize materials (e.g., maps, drawings, charts) are reproduced by sectioning the original, beginning at the upper left-hand comer and continuing from left to right in equal sections with small overlaps. Each original is also photographed in one exposure and is included in reduced form at the back of the book. Photographs included in the original manuscript have been reproduced xerographically in this copy. Higher quality 6” x 9” black and white photographic prints are available for any photographs or illustrations appearing in this copy for an additional charge. Contact UMI directly to order. UMI A Bell & Howell Information Compaiy 300 North Zed) Road, Ann Arbor MI 48106-1346 USA 313/761-4700 800/521-0600 RELATIVISTIC EFFECTIVE CORE POTENTIALS AND THE THEORETICAL CHEMISTRY OF THE TRANSACTINIDE ELEMENTS Dissertation Presented in Partial Fulfillment of the Requirements for the Degree of Doctor of Philosophy in the Graduate School of the Ohio State University By Clinton Scott Nash, B.
    [Show full text]
  • Harnessed Atom: Nuclear Energy & Electricity Photosynthesis Biomass Is the Name for Materials from Plants and Animals That Have Chemical Energy Stored in Them
    Table of Contents Lesson 1 - Energy Basics Lesson 2 - Electricity Basics Lesson 3 - Atoms and Isotopes Lesson 4 - Ionizing Radiation Lesson 5 - Fission, Chain Reactions Lesson 6 - Atom to Electricity Lesson 7 - Waste from Nuclear Power Plants Lesson 8 - Concerns Lesson 9 - Energy and You Lesson 1 ENERGY BASICS Radiant Chemical Energy Energy Mechanical Energy Introduction This lesson will look at the states and forms of energy. Next we will look at where energy comes from. Finally, we’ll explore how the way we live is tied to our energy supply and what that means for the future. TOPICS: States of energy What is energy? Potential Energy is the ability to do work. But We use energy all the time. Whenever Kinetic what does that really mean? work is done, energy is used. All activities Forms of energy Mechanical involve energy. Chemical You might think of work as cleaning your Nuclear Electrical room, cutting the grass, or studying for a We need energy to Radiant test. And all these require energy. • power our factories and businesses Energy from gravity • heat and light our homes and schools Thermal Energy sources To a scientist, “work” means something • run our appliances and machines Primary and secondary more exact. Work is causing a change. It • stay alive and keep our bodies moving sources Renewable vs non- can be a change in position, like standing • build and fuel our cars, trucks, planes, renewable up or moving clothes from the floor to and ships Conversion Conservation the laundry basket. It can be a change in • run television and videos Environmental effects temperature, like heating water for a cup • power our phones, computers, music, Greenhouse effect of tea.
    [Show full text]
  • The Actinide Research Quarterly Guest Editorial Managing and Minimizing Radioactive Waste Continue to Challenge the DOE Complex
    Fall 1996 Los Alamos National Laboratory • A U.S. Department of Energy Laboratory The Actinide Research T55A Quarterly o f t h e N u c l e a r M a t e r i a l s T e c h n o l o g y D i v i s i o n In This Issue NMT's Contributions to the Cassini Saturn Mission Follow Division's Space Exploration Tradition 1 NMT's Contributions Some of NMT Division’s handiwork will longer thereafter at reduced levels. For the to the Cassini Saturn be soaring across the solar system on its way Cassini mission, radioisotope thermoelectric Mission Follow to Saturn in the near future. Many NMT generators (RTGs) will provide the electrical Division's Space members, primarily in Actinide Ceramics and energy needed, while lightweight radioisotope Exploration Tradition Fabrication (NMT-9), have produced special heating units (LWRHUs, or RHUs for short), heat and energy sources to help keep things will keep equipment warm enough to 2 running aboard the Cassini orbiter and function. Managing and Huygens probe, which will be launched in Cassini will use three RTGs, which con- Minimizing Radioac- October of 1997 toward the Saturnian system vert thermal energy from plutonium decay tive Waste Continue to explore the gas giant, its mysterious rings, into electrical energy. Each RTG contains 72 to Challenge the DOE and some of its frigid moons. small pellets of plutonium-238 dioxide, each Complex Because Saturn is so far away from the about the size of a marshmallow and weigh- sun, solar rays there are only a small fraction ing 150 grams.
    [Show full text]
  • Reprocessing of Nudear Fuels by Fluoride Volatilization with Sulfur Hexafluoride
    Institut für Chemische Technologie KERNFORSCHUNGSANLAGE JOLICH des Landes Nordrhein-Westfalen - e.V. Reprocessing of Nudear Fuels by Fluoride Volatilization with Sulfur Hexafluoride by 0. Knacke, M. Laser, E. Merz and H. J. Riedel Jül - 408 - CT 1965 Aus: Proceedings of the conference nFuel cycles of high temperature gas-cooled reactors. n Brussels: Euratom 1965. S. 239-243. Berichte der Kernforschungsanlage Jülich Nr. 408 Institut für Chemische Technologie Jül - 408 - CT Dok.: Nuclear Fuels - Reprocessing Nuclear Fuels - Fluoride Volatilization DK: 621.039.59 621.039.54: 546.16: 536.423.1 Zu beziehen durch: ZENTRALBIBLIOTHEK der Kernforschungsanlage Jülich, Jülich, Bundesrepublik Deutschland REPROCESSING OF NUCLEAR FUELS BY FLUORIDE VOLATILIZATION WITH SULFUR HEXAFLUORIDE 0. KNACKE, M. LASER, E. MERZ and H. J. RIEDEL Arbeitsgruppe Institut für Chemische Technologie, Kernforschungsanlage Jülich, Germany ABSTRACT A new procedure was developed for the reprocessing of nuclear fuels by fluo­ ride volatilization, based on the fact that uranium or other uranium containing fuels can be fluorinated in a single step to uranium hexafluoride with sulfur hexa­ fluoride at temperatures above 800° C. The essential reactions taking place can be represented by the following equations : U02 + SF6 --+ UF6 + S02 UC2 + SF6 + 302 ---+ UF6 + 2C02 + S02 U + SF6 + 0 2 ---+ UF6 + S02 Advantageous for the use of sulfur hexafluoride is its property to be non­ corrosive up to temperatures of about 500° C. In order to perform the process, the fuels are first pulverized in a known manner and then fluorinated either with pure sulfur hexafluoride alone or together with oxidation agents like oxygen, air, manganese dioxide or others. The fluorination can be done in two steps.
    [Show full text]
  • A Periodic Table of the Elements at Los Alamos National Laboratory Los Alamos National Laboratory's Chemistry Division Presents Periodic Table of the Elements
    A Periodic Table of the Elements at Los Alamos National Laboratory Los Alamos National Laboratory's Chemistry Division Presents Periodic Table of the Elements A Resource for Elementary, Middle School, and High School Students Click an element for more information: Group** Period 1 18 IA VIIIA 1A 8A 1 2 13 14 15 16 17 2 1 H IIA IIIA IVA VA VIA VIIA He 1.008 2A 3A 4A 5A 6A 7A 4.003 3 4 5 6 7 8 9 10 2 Li Be B C N O F Ne 6.941 9.012 10.81 12.01 14.0116.00 19.00 20.18 11 12 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 3 Na Mg IIIB IVB VB VIB VIIB------- VIII ------ IB IIB Al Si P S Cl Ar 22.99 24.31 3B 4B 5B 6B 7B - 1B 2B 26.98 28.09 30.9732.07 35.45 39.95 ------- 8 ------- 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 4 K Ca Sc Ti V Cr Mn Fe Co Ni Cu Zn Ga Ge As Se Br Kr 39.10 40.08 44.96 47.8850.94 52.00 54.94 55.85 58.47 58.6963.5565.39 69.72 72.59 74.9278.96 79.90 83.80 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 5 Rb Sr Y Zr NbMo Tc Ru Rh Pd AgCd In Sn Sb Te I Xe 85.47 87.62 88.91 91.2292.91 95.94 (98) 101.1 102.9 106.4107.9112.4 114.8 118.7 121.8127.6 126.9 131.3 55 56 57 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 6 Cs Ba La* Hf Ta W Re Os Ir Pt AuHg Tl Pb Bi Po At Rn 132.9 137.3 138.9 178.5180.9 183.9 186.2 190.2 190.2 195.1197.0200.5 204.4 207.2 209.0 (210) (210) (222) 87 88 89 104 105 106 107 108 109 110 111 112 114 116 118 7 Fr Ra Ac~ Rf Db Sg Bh Hs Mt --- --- --- --- --- --- (223) (226) (227) (257) (260) (263) (262) (265) (266) () () () () () () http://periodic.lanl.gov/default.htm (1 of 3) [10/24/2001 5:40:02 PM] A Periodic Table of the Elements at Los Alamos National Laboratory 58 59 60 61 62 63 64 65 66 67 68 69 70 71 Lanthanide Series* Ce Pr NdPmSm Eu Gd Tb DyHo Er Tm Yb Lu 140.1 140.9144.2 (147) 150.4 152.0 157.3 158.9162.5164.9 167.3 168.9 173.0175.0 90 91 92 93 94 95 96 97 98 99 100 101 102 103 Actinide Series~ Th Pa U Np Pu AmCmBk Cf Es FmMdNo Lr 232.0 (231) (238) (237) (242) (243) (247) (247) (249) (254) (253) (256) (254) (257) ** Groups are noted by 3 notation conventions.
    [Show full text]
  • STAAR® Grade 8 Science Admin. May 2018 Released
    STAAR® State of Texas Assessments of Academic Readiness GRADE 8 Science Administered May 2018 RELEASED Copyright © 2018, Texas Education Agency. All rights reserved. Reproduction of all or portions of this work is prohibited without express written permission from the Texas Education Agency. -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- STAAR GRADE 8 SCIENCE STAAR State of Texas REFERENCE MATERIALS Assessments of Academic Readiness FORMULAS mass Density = volume total distance Average speed = total time Net force = (mass)(acceleration) Work = (force)(distance) 1 18 1A 8A 1 Atomic number 14 2 1 H He 2 Symbol 13 14 15 16 17 1.008 Si 4.0026 Hydrogen 2A 3A 4A 5A 6A 7A Atomic mass 28.085 Helium 3 4 5 6 7 8 9 10 Silicon Name 2 Li Be B C N O F Ne 6.94 9.0122 10.81 12.011 14.007 15.999 18.998 20.180 Lithium Beryllium Boron Carbon Nitrogen Oxygen Fluorine Neon 11 12 13 14 15 16 17 18 3 Na Mg Al Si P S Cl Ar 3 4 5 6 7 22.990 24.305 8 9 10 11 12 26.982 28.085 30.974 32.06 35.45 39.948 Sodium Magnesium 3B 4B 5B 6B 7B 8B 1B 2B Aluminum Silicon Phosphorus Sulfur Chlorine Argon 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 4 K Ca Sc Ti V Cr Mn Fe Co Ni Cu Zn Ga Ge As Se Br Kr 39.098 40.078 44.956 47.867 50.942 51.996 54.938 55.845 58.933 58.693 63.546 65.38 69.723 72.630 74.922 78.971 79.904 83.798 Potassium Calcium Scandium Titanium Vanadium Chromium Manganese Iron Cobalt Nickel Copper Zinc Gallium Germanium
    [Show full text]
  • Density Functional Study of Sulfur Hexafluoride (SF6) and Its Hydrogen Derivatives Jacek Piechota, Marta Kinga Bruska
    Density Functional Study of Sulfur Hexafluoride (SF6) and its Hydrogen Derivatives Jacek Piechota, Marta Kinga Bruska To cite this version: Jacek Piechota, Marta Kinga Bruska. Density Functional Study of Sulfur Hexafluoride (SF6) and its Hydrogen Derivatives. Molecular Simulation, Taylor & Francis, 2008, 34 (10-15), pp.1041-1050. 10.1080/08927020802258708. hal-00515048 HAL Id: hal-00515048 https://hal.archives-ouvertes.fr/hal-00515048 Submitted on 4 Sep 2010 HAL is a multi-disciplinary open access L’archive ouverte pluridisciplinaire HAL, est archive for the deposit and dissemination of sci- destinée au dépôt et à la diffusion de documents entific research documents, whether they are pub- scientifiques de niveau recherche, publiés ou non, lished or not. The documents may come from émanant des établissements d’enseignement et de teaching and research institutions in France or recherche français ou étrangers, des laboratoires abroad, or from public or private research centers. publics ou privés. For Peer Review Only Density Functional Study of Sulfur Hexafluoride (SF6) and its Hydrogen Derivatives Journal: Molecular Simulation/Journal of Experimental Nanoscience Manuscript ID: GMOS-2008-0043.R1 Journal: Molecular Simulation Date Submitted by the 15-May-2008 Author: Complete List of Authors: Piechota, Jacek; University of Warsaw, ICMM Bruska, Marta; Jagiellonian University, Department of Chemistry Keywords: sulfur hexafluoride, greenhouse gases, density functional theory Note: The following files were submitted by the author for peer review, but cannot be converted to PDF. You must view these files (e.g. movies) online. SF6_Bruska_Piechota_figures.rar SF6_Bruska_Piechota_update_figures.tar http://mc.manuscriptcentral.com/tandf/jenmol Page 1 of 30 1 2 "Catchline" (i.e.
    [Show full text]
  • Actinide Separation Nuclear Waste Streams and Materials
    science XN9800106 OCDE Actinide Separation Nuclear Waste Streams and Materials 29-3 NEA NUCLEAR ENERGY AGENCY O M NEA/NSC/DOC(97)19 NEA NUCLEAR SCIENCE COMMITTEE ACTEVIDE SEPARATION CHEMISTRY IN NUCLEAR WASTE STREAMS AND MATERIALS December 1997 NUCLEAR ENERGY AGENCY ORGANISATION FOR ECONOMIC CO-OPERATION AND DEVELOPMENT ORGANISATION AN Pursuant to Article 1 of the Convention signed in Paris on 14th December 1960, and which came into force on 30th September 1961, the Organisation for Economic Co-operation and Development (OECD) shall promote policies designed: — to achieve the highest sustainable economic growth and employment and a rising standard of living in Member countries, while maintaining financial stability, and thus to contribute to the development of the world economy; — to contribute to sound economic expansion in Member as well as non-member countries in the process of economic development; and — to contribute to the expansion of world trade on a multilateral, non-discriminatory basis in accordance with international obligations. The original Member countries of the OECD are Austria, Belgium, Canada, Denmark, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, the Netherlands, Norway, Portugal, Spain, Sweden, Switzerland, Turkey, the United Kingdom and the United States. The following countries became Members subsequently through accession at the dates indicated hereafter: Japan (28th April 1964), Finland (28th January 1969), Australia (7th June 1971), New Zealand (29th May 1973), Mexico (18th May 1994) the Czech Republic (21st December 1995), Hungary (7th May 1996), Poland (22nd November 1996) and the Republic of Korea (12th December 1996). The Commission of the European Communities takes part in the work of the OECD (Article 13 of the OECD Convention).
    [Show full text]