Of the Periodic Table
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Neutron Stars
Chandra X-Ray Observatory X-Ray Astronomy Field Guide Neutron Stars Ordinary matter, or the stuff we and everything around us is made of, consists largely of empty space. Even a rock is mostly empty space. This is because matter is made of atoms. An atom is a cloud of electrons orbiting around a nucleus composed of protons and neutrons. The nucleus contains more than 99.9 percent of the mass of an atom, yet it has a diameter of only 1/100,000 that of the electron cloud. The electrons themselves take up little space, but the pattern of their orbit defines the size of the atom, which is therefore 99.9999999999999% Chandra Image of Vela Pulsar open space! (NASA/PSU/G.Pavlov et al. What we perceive as painfully solid when we bump against a rock is really a hurly-burly of electrons moving through empty space so fast that we can't see—or feel—the emptiness. What would matter look like if it weren't empty, if we could crush the electron cloud down to the size of the nucleus? Suppose we could generate a force strong enough to crush all the emptiness out of a rock roughly the size of a football stadium. The rock would be squeezed down to the size of a grain of sand and would still weigh 4 million tons! Such extreme forces occur in nature when the central part of a massive star collapses to form a neutron star. The atoms are crushed completely, and the electrons are jammed inside the protons to form a star composed almost entirely of neutrons. -
The Lithium, Boron and Beryllium Content Of
Published in Geochimica et Cosmochimica Acta 72, issue 22, 5475-5504, 2008 1 which should be used for any reference to this work The Lithium, Boron and Beryllium content of serpentinized peridotites from ODP Leg 209 (Sites 1272A and 1274A): Implications for lithium and boron budgets of oceanic lithosphere Flurin Vils a,*, Laure Pelletier a, Angelika Kalt a, Othmar Mu¨ntener b, Thomas Ludwig c a Institut de Ge´ologie et d’Hydroge´ologie, Universite´ de Neuchaˆtel, Rue Emile-Argand 11, CP 158, CH-2009 Neuchaˆtel, Switzerland b Institut de Mine´ralogie et Ge´ochimie, Universite´ de Lausanne, Anthropole, CH-1015 Lausanne, Switzerland c Mineralogisches Institut, Ruprecht-Karls-Universita¨t Heidelberg, Im Neuenheimer Feld 236, D-69120 Heidelberg, Germany Abstract Despite the key importance of altered oceanic mantle as a repository and carrier of light elements (B, Li, and Be) to depth, its inventory of these elements has hardly been explored and quantified. In order to constrain the systematics and budget of these elements we have studied samples of highly serpentinized (>50%) spinel harzburgite drilled at the Mid-Atlantic Ridge (Fifteen– Twenty Fracture zone, ODP Leg 209, Sites 1272A and 1274A). In-situ analysis by secondary ion mass spectrometry reveals that the B, Li and Be contents of mantle minerals (olivine, orthopyroxene, and clinopyroxene) remain unchanged during serpent- inization. B and Li abundances largely correspond to those of unaltered mantle minerals whereas Be is close to the detection limit. The Li contents of clinopyroxene are slightly higher (0.44–2.8 lggÀ1) compared to unaltered mantle clinopyroxene, and olivine and clinopyroxene show an inverse Li partitioning compared to literature data. -
IA Metals: Alkali Metals
IA Metals: Alkali Metals INTRODUCTION: The alkali metals are a group in the periodic table consisting of the chemical elements lithium (Li), sodium (Na), potassium (K), rubidium (Rb), caesium (Cs). You should remember that there is a separate group called the alkaline earth metals in Group Two. They are a very different family, even though they have a similar name. The seventh member of alkali metals group – francium, is radioactive and so rare that only 20 atoms of francium may exist on Earth at any given moment. The term alkali is derived from an Arabic word meaning “ashes.” PHYSICAL PROPERTIES: Shiny Soft (They can all be cut easily with a knife ) Highly reactive at standard temperature and pressure Because of their high reactivity, they must be stored under oil to prevent reaction with air Their density increases as we move from Li to F White/metal coloured Very good conductors of heat and electricity Have the ability to impart colour to the flame. This property of alkali metals is used in their identification. CHEMICAL PROPERTIES: The atom of any given alkali metal has only one valence electron. The chemical reactivity of alkali metals increase as we move from the top to the bottom of the group. Like any other metals, ionization potential is very low. In fact, alkali metals have the lowest ionization potential among the elements of any given period of the periodic table. Any alkali metal when comes in contact with air or oxygen, starts burning and oxides are formed in the process. At the end of the chemical reaction, lithium gives lithium monoxide (LiO), sodium gives sodium peroxide (Na2O2) and other alkali metals give superoxides. -
Identification and Quantification of Arsenic Species in Gold Mine Wastes Using Synchrotron-Based X-Ray Techniques
Identification and Quantification of Arsenic Species in Gold Mine Wastes Using Synchrotron-Based X-ray Techniques Andrea L. Foster, PhD U.S. Geological Survey GMEG Menlo Park, CA Arsenic is an element of concern in mined gold deposits around the world Spenceville (Cu-Au-Ag) Lava Cap (Nevada) Ketza River (Au) Empire Mine (Nevada) low-sulfide, qtz Au sulfide and oxide ore Argonaut Mine (Au) bodies Don Pedro Harvard/Jamestown Ruth Mine (Cu) Kelly/Rand (Au/Ag) Goldenville, Caribou, and Montague (Au) The common arsenic-rich particles in hard-rock gold mines have long been known Primary Secondary Secondary/Tertiary Iron oxyhydroxide (“rust”) “arsenian” pyrite containing arsenic up to 20 wt% -1 Scorodite FeAsO 2H O As pyrite Fe(As,S)2 4 2 Kankite : FeAsO4•3.5H2O Reich and Becker (2006): maximum of 6% As-1 Arseniosiderite Ca2Fe3(AsO4)3O2·3H2O Arsenopyrite FeAsS Jarosite KFe3(SO4)2(OH)6 Yukonite Ca7Fe12(AsO4)10(OH)20•15H2O Tooleite [Fe6(AsO3)4(SO4)(OH)4•4H2O Pharmacosiderite KFe (AsO ) (OH) •6–7H O arsenide n- 4 4 3 4 2 n = 1-3 But it is still difficult to predict with an acceptable degree of uncertainty which forms will be present • thermodynamic data lacking or unreliable for many important phases • kinetic barriers to equilibrium • changing geochemical conditions (tailings management) Langmuir et al. (2006) GCA v70 Lava Cap Mine Superfund Site, Nevada Cty, CA Typical exposure pathways at arsenic-contaminated sites are linked to particles and their dissolution in aqueous fluids ingestion of arsenic-bearing water dissolution near-neutral, low -
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. -
Suppression Mechanisms of Alkali Metal Compounds
SUPPRESSION MECHANISMS OF ALKALI METAL COMPOUNDS Bradley A. Williams and James W. Fleming Chemistry Division, Code 61x5 US Naval Research Lnhoratory Washington, DC 20375-5342, USA INTRODUCTION Alkali metal compounds, particularly those of sodium and potassium, are widely used as fire suppressants. Of particular note is that small NuHCOi particles have been found to be 2-4 times more effective by mass than Halon 1301 in extinguishing both eountertlow flames [ I] and cup- burner flames [?]. Furthermore, studies in our laboratory have found that potassium bicarbonate is some 2.5 times more efficient by weight at suppression than sodium bicarhonatc. The primary limitation associated with the use of alkali metal compounds is dispersal. since all known compounds have very low volatility and must he delivered to the fire either as powders or in (usually aqueous) solution. Although powders based on alkali metals have been used for many years, their mode of effective- ness has not generally been agreed upon. Thermal effects [3],namely, the vaporization of the particles as well as radiative energy transfer out of the flame. and both homogeneous (gas phase) and heterogeneous (surface) chemistry have been postulated as mechanisms by which alkali metals suppress fires [4]. Complicating these issues is the fact that for powders, particle size and morphology have been found to affect the suppression properties significantly [I]. In addition to sodium and potassium, other alkali metals have been studied, albeit to a consider- ably lesser extent. The general finding is that the suppression effectiveness increases with atomic weight: potassium is more effective than sodium, which is in turn more effective than lithium [4]. -
Unit 3 Notes: Periodic Table Notes John Newlands Proposed an Organization System Based on Increasing Atomic Mass in 1864
Unit 3 Notes: Periodic Table Notes John Newlands proposed an organization system based on increasing atomic mass in 1864. He noticed that both the chemical and physical properties repeated every 8 elements and called this the ____Law of Octaves ___________. In 1869 both Lothar Meyer and Dmitri Mendeleev showed a connection between atomic mass and an element’s properties. Mendeleev published first, and is given credit for this. He also noticed a periodic pattern when elements were ordered by increasing ___Atomic Mass _______________________________. By arranging elements in order of increasing atomic mass into columns, Mendeleev created the first Periodic Table. This table also predicted the existence and properties of undiscovered elements. After many new elements were discovered, it appeared that a number of elements were out of order based on their _____Properties_________. In 1913 Henry Mosley discovered that each element contains a unique number of ___Protons________________. By rearranging the elements based on _________Atomic Number___, the problems with the Periodic Table were corrected. This new arrangement creates a periodic repetition of both physical and chemical properties known as the ____Periodic Law___. Periods are the ____Rows_____ Groups/Families are the Columns Valence electrons across a period are There are equal numbers of valence in the same energy level electrons in a group. 1 When elements are arranged in order of increasing _Atomic Number_, there is a periodic repetition of their physical and chemical -
The Periodic Table
THE PERIODIC TABLE Dr Marius K Mutorwa [email protected] COURSE CONTENT 1. History of the atom 2. Sub-atomic Particles protons, electrons and neutrons 3. Atomic number and Mass number 4. Isotopes and Ions 5. Periodic Table Groups and Periods 6. Properties of metals and non-metals 7. Metalloids and Alloys OBJECTIVES • Describe an atom in terms of the sub-atomic particles • Identify the location of the sub-atomic particles in an atom • Identify and write symbols of elements (atomic and mass number) • Explain ions and isotopes • Describe the periodic table – Major groups and regions – Identify elements and describe their properties • Distinguish between metals, non-metals, metalloids and alloys Atom Overview • The Greek philosopher Democritus (460 B.C. – 370 B.C.) was among the first to suggest the existence of atoms (from the Greek word “atomos”) – He believed that atoms were indivisible and indestructible – His ideas did agree with later scientific theory, but did not explain chemical behavior, and was not based on the scientific method – but just philosophy John Dalton(1766-1844) In 1803, he proposed : 1. All matter is composed of atoms. 2. Atoms cannot be created or destroyed. 3. All the atoms of an element are identical. 4. The atoms of different elements are different. 5. When chemical reactions take place, atoms of different elements join together to form compounds. J.J.Thomson (1856-1940) 1. Proposed the first model of the atom. 2. 1897- Thomson discovered the electron (negatively- charged) – cathode rays 3. Thomson suggested that an atom is a positively- charged sphere with electrons embedded in it. -
Arsenic and Lead Contamination in Oklahoma Soils Arsenic and Lead Are Naturally Occurring Elements Present in Rocks
Arsenic and Lead Contamination in Oklahoma Soils Arsenic and lead are naturally occurring elements present in rocks. As these rocks erode, arsenic and lead get in soils, waters and plants. The United States Geological Survey (USGS) reports an average of 7.4 parts per million (ppm) as the arsenic concentration in soils for the entire United States and 7.2 ppm as the average arsenic concentration in soils for the western U.S.(1) Background arsenic concentrations in Central Oklahoma soils range from 0.6 to 21 ppm.(2) The USGS reports an average lead concentration of 13 parts per million (ppm) in soils for central Oklahoma(2) and an average lead concentration of 18 ppm for the Western United States.(3) Pollution from historic lead and zinc smelters in Oklahoma left residues of lead, arsenic and cadmium in area soils. Contamination was also spread by using smelter debris as fill material, driveways and roads. These former smelters were primarily located in eastern Oklahoma. Some arsenic contamination above naturally occurring levels is also attributed to agricultural, energy and industrial practices. For example, arsenic-containing insecticides and herbicides were widely used on vegetables, fruits and field crops from the 1900s to around 1950. Coal combustion, wood preserving and smelting operations are known to be sources of arsenic contamination.(1) Lead was once commonly used in paint and in plumbing. Lead was an additive to gasoline for many years and has also been found in ceramics, mini-blinds and other products. Homes built before 1970 commonly have lead-based paint. Renovation activities and peeling or flaking paint can release lead inside the home. -
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. -
FRANCIUM Element Symbol: Fr Atomic Number: 87
FRANCIUM Element Symbol: Fr Atomic Number: 87 An initiative of IYC 2011 brought to you by the RACI KAYE GREEN www.raci.org.au FRANCIUM Element symbol: Fr Atomic number: 87 Francium (previously known as eka-cesium and actinium K) is a radioactive metal and the second rarest naturally occurring element after Astatine. It is the least stable of the first 103 elements. Very little is known of the physical and chemical properties of Francium compared to other elements. Francium was discovered by Marguerite Perey of the Curie Institute in Paris, France in 1939. However, the existence of an element of atomic number 87 was predicted in the 1870s by Dmitri Mendeleev, creator of the first version of the periodic table, who presumed it would have chemical and physical properties similar to Cesium. Several research teams attempted to isolate this missing element, and there were at least four false claims of discovery during which it was named Russium (after the home country of soviet chemist D. K. Dobroserdov), Alkalinium (by English chemists Gerald J. K. Druce and Frederick H. Loring as the heaviest alkali metal), Virginium (after Virginia, home state of chemist Fred Allison), and Moldavium (by Horia Hulubei and Yvette Cauchois after Moldavia, the Romanian province where they conducted their work). Perey finally discovered Francium after purifying radioactive Actinium-227 from Lanthanum, and detecting particles decaying at low energy levels not previously identified. The new product exhibited chemical properties of an alkali metal (such as co-precipitating with Cesium salts), which led Perey to believe that it was element 87, caused by the alpha radioactive decay of Actinium-227. -
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