DOCSLIB.ORG

The New Element Berkelium (Atomic Number 9'7)*

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
The New Element Berkelium (Atomic Number 9'7)* NEW ELE MENT BE RKELI U M 781 From peak XI in Fig. 6 and IX in Fig. 7, which are V. CONCLUSION due to the elastic scattering of alpha-particles from The 1.0-Mev level in C" has been conlrmed, and a gold, it was found necessary to modify the range-energy new level at 6.8 Mev has been determined. The proton of Lattes' Other evidence as to curve at higher energies. group giving rise to the 1.0-Mev level is small statis- alpha-alpha-bom- a need for modification came from an tically, consisting of only approximately 11 tracks at bardment when the recoil.ing and scattered particles 115', yet this number is large compared to the expected were recorded at small angles. The observed ranges fell background at this range and is an appreciable fraction short of the predicted ranges when Lattes' curve was of the 33 proton tracks observed which resulted from used. This was true for the three aforementioned cases C" in the ground state. A level in C" at 3.58 Mev has even after all possible corrections were made. If the been found at 90' but the results are doubtful because beam energy were lower than 20 Mev, i.e., 17.5 Mev, of non-appearance at 115' and 155' or under alpha- then XI in Fig. 6 and IX in Fig. 7 would be correctly particle bombardment. The relative scattering of deu- identi6ed but then the other in 6 and 7 peaks Figs. terons and alpha-particles from nuclei in the ground would be displaced too far to the right. Therefore it was state and in the various nuclear energy levels are illus- assumed that the bombarding energy was 20 Mev, that trated. The results indicate that 10-Mev deuterons are the lower portion of the alpha-energy range curve, more effective in studying energy levels than are 20-Mev below 10 Mev, was correct, but that above 10 Mev a the modification was necessary. This modification was alpha-particles. Finally alpha-particle range-energy Ilford E-1 nuclear has made from the proton range-energy curve by assuming curve, as applied to emulsions, that an alpha-particle and a proton of the same velocity been modihed at higher energies for alpha-particles. have the same range. The corrected curve has already This author wishes to thank Messrs. Chia-Hua Chang been published. and Wen-Jsao Yang for their careful reading of the plates, and Dr. Robert N. Varney for his constructive g Lattes, Fowler, and Cuer, Proc. Phys. Soc. London 59, 883 (1947). criticism. P H YSI CAL R EVI EW VOLUME 80, NUMBER 5 DECEMBER 1, 1950 The New Element Berkelium (Atomic Number 9'7)* S. G. THoMPsoN, A. GHIoRso) AND G. T. SEABoRG Radiation Laboratory and Department of Chemistry, University of California, Berkeley, California (Received July 24, 1950) An isotope of the element with atomic number 97 has been discovered as a product of the helium ion bombardment of americium. This isotope decays with the emission of alpha-particles of maximum energy 6.72 Mev (30 percent) and it emits lower energy alpha-particles of energies 6.55 Mev (53 percent) and 6.20 Mev (17 percent). The half-life of this isotope is 4.6+0.2 hr. and it decays primarily by electron cap- ture with about 0.1 percent branching decay by alpha-particle emission. The mass number is probably 243 as indicated by chemical separation of the alpha-particle and electron-capture daughters. The name berkelium, symbol Bk, is proposed for element 97. The chemical separation of element 97 from the target material and other reaction products was made by combinations of precipitation and ion exchange adsorption methods making use of its anticipated (III) and (IV) oxidation states and its position as a member of the actinide transition series. The distinctive chemical properties made use of in its separation and the equally distinctive decay properties of the particular isotope constitute the principal evidence for the new element. The isotope Cm~~ is identified experimentally as a result of its production as a decay product of Bk'~. The Cm'~ decays by the emission of alpha-particles of maximum energy 5.89 Mev {15percent) and lower energy alpha-particles of energy 5.79 Mev (85 percent); the half-life for alpha-particle emission is estimated to be roughly 100 yr. I. INTRODUCTION Seaborg, James, and Morgan. ' The search for trans- curium elements was begun us in the fall of 1945. ~ 'HE transuranium elements numbers 96, curium, by It was anticipated' that element 97 as eka-terbium in and 95, americium, were discovered in 1944, the the actinide transition series would possess oxidation first by Seaborg, James, and Ghiorso, ' the second by states (III) and (IV) with properties similar to curium *This work was performed under the auspices of the AEC. in the (III) oxidation state and to plutonium (IV) in ' Seaborg, James, and Ghiorsor The Transuranium E/ements: Re- search Papers (McGraw-Hill Book Company, Inc., New York, ' Seaborg, James, and Morgan, National Nuclear Energy Series, 1949), Paper No. 22.2, National Nuclear Energy Series, Plutonium see reference 1, Paper No. 22.1. Project Record, Vol. 148. ' G. T. Seaborg, Nucleonics 5, No. 5, 16 (1949). THOM PSON, GH IORSO, AN D SEABORG its (IV) oxidation state. It was more diKcult to esti- prior to December, 1949, were unsuccessful for many mate the oxidation potential of the (III)~(IV) couple reasons which may be grouped into three classes. First, but it was expected. that element 97 would be somewhat the methods of predicting the properties of the new easier to oxidize than terbium (III) which is not oxidiz- isotopes were relatively undeveloped and the experi- able to higher states in aqueous solution at all. The ments were never done with sufhcient speed. The fur- salient point is that if element 97 could not be con- ther development of the alpha-decay systematics4 made verted to an oxidation state higher than (III) in solu- it possible to estimate energies and half-lives for alpha- tions it would be extremely dificult to separate in a particle decay. The resulting estimated alpha-particle short period of time from rare earth elements and from decay energies could be used in calculating by closed the actinide elements from which it would be produced. decay cycles the total energies for electron-capture Americium is very difFicult and curium probably im- decay or beta-particle decay. An empirical method of possible to oxidize above the (III) state in aqueous estimating electron-capture half-lives from disintegra- solution. ' In other words, it appeared that it might be tion energies was also developed' which, although very necessary to use tedious rare earth separations in order rough due to uncertainties in the degree of prohibition to separate and identify the new element, the isotopes of this mode of decay in any given case, was very useful of which do not exist in nature and whose neutron- in making half-life estimates. deficient isotopes as produced by alpha-particle and The second major difhculty was that of obtaining deuteron bombardments would have short half-lives as suQiciently large amounts of americium and curium as a result of considerable instability toward alpha-par- sources for the production of element 97. Eventually ticle emission and electron-capture decay. americium became available in milligram amounts In view of the fact that sufFiciently intense beams of through neutron irradiation of plutonium. The isola- energetic particles of nuclear charge greater than two tion of the americium from the plutonium required were not available at the time of this research, it is tedious chemical procedures. The curium was produced obvious that there were only two methods of approach in smaller amounts by the irradiation of americium with to the production of element 97. The first approach was neutrons. " through the bombardment of americium with helium The intense radioactivity of the americium and ions or the bombardment of curium with deuterons or curium source materials presented the third major helium ions. The second (not yet successful) was through difhculty. This radioactivity necessitated not only the intensive neutron irradiations of curium in order to design and development of advanced techniques and produce eventually through successive (n, y) reactions equipment' for its safe handling, but also made it a curium isotope of mass sufhcient to be unstable toward necessary to attain enormous separation factors in the negative beta-particle decay and so to produce an iso- isolation of the new element from the target material tope of element 97. in order to be able to detect the small amounts of radio- Both methods were employed in attempting to ob- activity due to it. Furthermore, this high degree of serve element 97 and for each, diBerent chemical pro- separation had to be carried out in good yield in a cedures were used. Some of these procedures were de- short length of time. signed to separate the new element in oxidation states Essentially three chemical steps were developed to greater than (III) and others were used on the assump- solve these chemical problems. The conversion of the tion that element 97 existed in solution under most americium to a hexapositive oxidation state' was used conditions in the tripositive oxidation state. in the rapid removal of the bulk of the bombarded Although the broad assumptions made when the americium. An ion exchange method involving the work was started were all correct, the experiments done separation of the actinide elements as a group from the rare earth 6ssion products by elution with concentrated HCl from a cation exchange column' was exploited for the rapid separation of the tripositive actinide ele- ments.
Load more

Recommended publications
  • Table 2.Iii.1. Fissionable Isotopes1
    FISSIONABLE ISOTOPES Charles P. Blair Last revised: 2012 “While several isotopes are theoretically fissionable, RANNSAD defines fissionable isotopes as either uranium-233 or 235; plutonium 238, 239, 240, 241, or 242, or Americium-241. See, Ackerman, Asal, Bale, Blair and Rethemeyer, Anatomizing Radiological and Nuclear Non-State Adversaries: Identifying the Adversary, p. 99-101, footnote #10, TABLE 2.III.1. FISSIONABLE ISOTOPES1 Isotope Availability Possible Fission Bare Critical Weapon-types mass2 Uranium-233 MEDIUM: DOE reportedly stores Gun-type or implosion-type 15 kg more than one metric ton of U- 233.3 Uranium-235 HIGH: As of 2007, 1700 metric Gun-type or implosion-type 50 kg tons of HEU existed globally, in both civilian and military stocks.4 Plutonium- HIGH: A separated global stock of Implosion 10 kg 238 plutonium, both civilian and military, of over 500 tons.5 Implosion 10 kg Plutonium- Produced in military and civilian 239 reactor fuels. Typically, reactor Plutonium- grade plutonium (RGP) consists Implosion 40 kg 240 of roughly 60 percent plutonium- Plutonium- 239, 25 percent plutonium-240, Implosion 10-13 kg nine percent plutonium-241, five 241 percent plutonium-242 and one Plutonium- percent plutonium-2386 (these Implosion 89 -100 kg 242 percentages are influenced by how long the fuel is irradiated in the reactor).7 1 This table is drawn, in part, from Charles P. Blair, “Jihadists and Nuclear Weapons,” in Gary A. Ackerman and Jeremy Tamsett, ed., Jihadists and Weapons of Mass Destruction: A Growing Threat (New York: Taylor and Francis, 2009), pp. 196-197. See also, David Albright N 2 “Bare critical mass” refers to the absence of an initiator or a reflector.
    [Show full text]
  • Genius of the Periodic Table
    GENIUS OF THE PERIODIC TABLE "Isn't it the work of a genius'. " exclaimed Academician V.I. Spitsyn, USSR, a member of the Scientific Advisory Committee when talking to an Agency audience in January. His listeners shared his enthusiasm. Academician Spitsyn was referring to the to the first formulation a hundred years ago by Professor Dmitry I. Mendeleyev of the Periodic Law of Elements. In conditions of enormous difficulty, considering the lack of data on atomic weights of elements, Mendeleyev created in less than two years work at St. Petersburg University, a system of chemical elements that is, in general, still being used. His law became a powerful instrument for further development of chemistry and physics. He was able immediately to correct the atomic weight numbers of some elements, including uranium, whose atomic weight he found to be double that given at the time. Two years later Mendeleyev went so far as to give a detailed description of physical or chemical properties of some elements which were as yet undiscovered. Time gave striking proof of his predictions and his periodic law. Mendeleyev published his conclusions in the first place by sending, early in March 186 9, a leaflet to many Russian and foreign scientists. It gave his system of elements based on their atomic weights and chemical resemblance. On the 18th March that year his paper on the subject was read at the meeting of the Russian Chemical Society, and two months later the Society's Journal published his article entitled "The correlation between properties of elements and their atomic weight".
    [Show full text]
  • Peaceful Berkelium
    in your element Peaceful berkelium The first new element produced after the Second World War has led a rather peaceful life since entering the period table — until it became the target of those producing superheavy elements, as Andreas Trabesinger describes. f nomenclature were transitive, element 97 with the finding that in Bk(iii) compounds would be named after an Irish bishop spin–orbit coupling leads to a mixing of the Iwhose philosophical belief was that first excited state and the ground state. This material things do not exist. But between gives rise to unexpected electronic properties the immaterialist George Berkeley and the not present in analogous lanthanide element berkelium stands, of course, the structures containing terbium. Even more fine Californian city of Berkeley (pictured), recently5, a combined experimental and where the element was first produced in computational study revealed that berkelium December 1949. The city became the eponym can have stabilized +iii and +iV oxidation of element 97 “in a manner similar to that states also under mild aqueous conditions, used in naming its chemical homologue indicating a path to separating it from other terbium […] whose name was derived from lanthanides and actinides. the town of Ytterby, Sweden, where the rare The main use of berkelium, however — earth minerals were first found”1. arguably one that wouldn’t have met with A great honour for the city? The mayor Bishop Berkeley’s approval — remains a of Berkeley at the time reportedly displayed PHOTO STOCK / ALAMY AF ARCHIVE distinctly material one: as the target for “a complete lack of interest when he was the synthesis of other transuranium and called with the glad tidings”2.
    [Show full text]
  • BNL-79513-2007-CP Standard Atomic Weights Tables 2007 Abridged To
    BNL-79513-2007-CP Standard Atomic Weights Tables 2007 Abridged to Four and Five Significant Figures Norman E. Holden Energy Sciences & Technology Department National Nuclear Data Center Brookhaven National Laboratory P.O. Box 5000 Upton, NY 11973-5000 www.bnl.gov Prepared for the 44th IUPAC General Assembly, in Torino, Italy August 2007 Notice: This manuscript has been authored by employees of Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy. The publisher by accepting the manuscript for publication acknowledges that the United States Government retains a non-exclusive, paid-up, irrevocable, world-wide license to publish or reproduce the published form of this manuscript, or allow others to do so, for United States Government purposes. This preprint is intended for publication in a journal or proceedings. Since changes may be made before publication, it may not be cited or reproduced without the author’s permission. DISCLAIMER This report was prepared as an account of work sponsored by an agency of the United States Government. Neither the United States Government nor any agency thereof, nor any of their employees, nor any of their contractors, subcontractors, or their employees, makes any warranty, express or implied, or assumes any legal liability or responsibility for the accuracy, completeness, or any third party’s use or the results of such use of any information, apparatus, product, or process disclosed, or represents that its use would not infringe privately owned rights. Reference herein to any specific commercial product, process, or service by trade name, trademark, manufacturer, or otherwise, does not necessarily constitute or imply its endorsement, recommendation, or favoring by the United States Government or any agency thereof or its contractors or subcontractors.
    [Show full text]
  • Remarkable Complexation and Stabilization of Berkelium(IV) by A
    Remarkable complexation and stabilization of berkelium(IV) by a synthetic siderophore: An experimental and theoretical comparison with neighboring trivalent actinide elements Gauthier J-P. Deblonde1, Manuel Sturzbecher-Hoehne1, Peter B. Rupert,2 Dahlia D. An,1 Marie-Claire Illy,1 Corie Y. Ralston,3 Jiri Brabec,4 Wibe A. de Jong*,5 Roland K. Strong*,2 and Rebecca J. Abergel* 1 1 Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA 2 Division of Basic Science, Fred Hutchinson Cancer Research Center, Seattle, WA 98109, USA 3 Berkeley Center for Structural Biology, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA 4 J. Heyrovsky Institute of Physical Chemistry, 18223 Prague 8, Czech Republic 5 Computational Research Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA Keywords: Berkelium; Californium; Actinides; Chelation; Separation; Luminescence; Sensitization Page 1 Abstract Despite theoretical assertions of berkelium (Bk) being the only transplutonium element that can exhibit +III and +IV oxidation states in solution, evidence of a stable oxidized Bk chelate has so far been elusive. Using a siderophore derivative, stabilization of the heaviest 4+ ion of the periodic table was achieved under mild aqueous conditions. The resulting Bk(IV) complex exhibits unprecedented sensitized luminescence through ligand-to-metal energy transfer, but also inhibits Bk interactions with the protein siderocalin, a mammalian metal transporter. Formation of this neutral Bk(IV) coordination compound contrasts sharply with the corresponding negatively charged species incorporating neighboring trivalent americium, curium and californium (Cf), which are sequestered by siderocalin, as evidenced by Xray diffraction analysis of the Cf(III)-ligand-protein ternary adduct, the first example and crystallographic characterization of a Cf macromolecular assembly.
    [Show full text]
  • Ment 98), Einsteinium (Element 99), Fermium (Element 100), Mendelevium (Element Downloaded by Guest on September 26, 2021 472 PHYSICS: G
    VOL. 45, 1959 PHYSICS: G. T. SEABORG 471 of californium isotopes. The horizontal broken line labeled "0.02%" indicates the peak height for a group which would have that intensity relative to the total alpha particles. It is seen that the general background is considerably higher than this value, and, in fact, some of the peaks which are sketched in are hardly justifi- able in view of the scatter of the data. The bottom part of Figure 8 shows the same part of the spectrum taken under much improved conditions, as shown by the line illustrating the peak height of 0.02 per cent. All of the peaks are seen much more clearly and, in addition, one or two have showed up which were completely ob- scured under the other conditions. The principal change in technique which re- sulted in this improvement consisted of lining the interior of the spectrograph with very-low-atomic-number material which has the desirable effect of reducing low- angle scattering of alpha particles. In summary, we may say that during the past few years very important ad- vances in theory, as well as in experimental technique, are beginning to result in a systematic assignment of nuclear spectroscopic states and an interpretation of these states in terms of some detailed knowledge of nuclear structure. In this discussion, attention has been confined to one aspect of a very broad problem, namely, that having to do with spectroscopic states in the heavy-element region deduced from the alpha-decay process. There are many other experimental methods which are brought to bear on this problem, some of which have been touched upon in a peripheral sense in this discussion and others not mentioned at all.
    [Show full text]
  • Atomic Weights of the Elements 2011 (IUPAC Technical Report)*
    Pure Appl. Chem., Vol. 85, No. 5, pp. 1047–1078, 2013. http://dx.doi.org/10.1351/PAC-REP-13-03-02 © 2013 IUPAC, Publication date (Web): 29 April 2013 Atomic weights of the elements 2011 (IUPAC Technical Report)* Michael E. Wieser1,‡, Norman Holden2, Tyler B. Coplen3, John K. Böhlke3, Michael Berglund4, Willi A. Brand5, Paul De Bièvre6, Manfred Gröning7, Robert D. Loss8, Juris Meija9, Takafumi Hirata10, Thomas Prohaska11, Ronny Schoenberg12, Glenda O’Connor13, Thomas Walczyk14, Shige Yoneda15, and Xiang-Kun Zhu16 1Department of Physics and Astronomy, University of Calgary, Calgary, Canada; 2Brookhaven National Laboratory, Upton, NY, USA; 3U.S. Geological Survey, Reston, VA, USA; 4Institute for Reference Materials and Measurements, Geel, Belgium; 5Max Planck Institute for Biogeochemistry, Jena, Germany; 6Independent Consultant on MiC, Belgium; 7International Atomic Energy Agency, Seibersdorf, Austria; 8Department of Applied Physics, Curtin University of Technology, Perth, Australia; 9National Research Council of Canada, Ottawa, Canada; 10Kyoto University, Kyoto, Japan; 11Department of Chemistry, University of Natural Resources and Applied Life Sciences, Vienna, Austria; 12Institute for Geosciences, University of Tübingen, Tübingen, Germany; 13New Brunswick Laboratory, Argonne, IL, USA; 14Department of Chemistry (Science) and Department of Biochemistry (Medicine), National University of Singapore (NUS), Singapore; 15National Museum of Nature and Science, Tokyo, Japan; 16Chinese Academy of Geological Sciences, Beijing, China Abstract: The biennial review of atomic-weight determinations and other cognate data has resulted in changes for the standard atomic weights of five elements. The atomic weight of bromine has changed from 79.904(1) to the interval [79.901, 79.907], germanium from 72.63(1) to 72.630(8), indium from 114.818(3) to 114.818(1), magnesium from 24.3050(6) to the interval [24.304, 24.307], and mercury from 200.59(2) to 200.592(3).
    [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 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 2) [5/10/2001 3:08:31 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]
  • Transactinium Isotope Nuclear Data (Tnd)
    Reviewa PapeB5 , rMb Status of Transactinium Isotope Evaluated Neutro Energne Datth n yai Range 10"3 eV to 15 MeV S. Yiftah, Y. Gur and M. Caner Department of Nuclear Engineering Technion-Israel Institut Technologf eo y Haifa, Israel and Israel Atomic Energy Commission Soreq Nuclear Research Centre Yavne, Israel Abstract Large amounts of transactinium elements will be produced in the next 2S years in thermal power reactors, fast breeders, test reactors, special purpose reactors, thermonuclear explosions and improved heavy-ion accelerators e ablb o evaluateo t e T . , predict, compute and judge the effects and uses of these elements, the nuclear commu- nity needs fully evaluated nuclea re use b dats nuclea a do t a r input to all computations and evaluations. The sixteen transactinium ele- ments and two hundred isotopes known to-date are divided into three groups eighd an , t main application area e mentionear s d from which needs can be derived for measurements and evaluations. Existing evaluations are tabulated and analysed, and following a WRENDA minus CINDA descriptive equation, nine main conclusion recommendationd an s s are derived, amongst which a "world transactinium nuclear data evaluation program" and other specific items for IAEA future actions in this field. 1. INTRODUCTION Large amounts somn ,i e cases tonhundredd an s f kilogramso s f o , transactinium elements will be produced, whether we like it or not, in 165 the nex year5 t2 therman si l power reactors, fast power reactors, test reactors and special-purpose reactors. These elements will affect the behavior and operation of the reactors, the cost of the power produced, the content and disposal of the radioactive waste, Some of these elements will be used in space missions, cardiac pacemakers, artificial hearts, various industries, and remote unattended sources of power.
    [Show full text]
  • Einsteinium Declassified
    in your element Einsteinium declassified Discovered during secret testing by the United States, Joanne Redfern tells us about element 99 and why its namesake cautioned against the very technology that led to its creation. n the first of November 1952, in a top causes einsteinium to glow7. Furthermore, secret test known as Mike, the United because it decays rapidly into berkelium OStates detonated the ‘Sausage’ — the and californium, samples of einsteinium are world’s first hydrogen bomb. The explosion nearly always contaminated. annihilated the entire Pacific island of Einsteinium is mainly used to make Elugelab, but it wasn’t all devastation; at heavier elements, such as mendelevium — the same time it created two new elements first discovered by Ghiorso’s team when that their discoverers would later name bombarding 253Es with alpha particles. In einsteinium and fermium. The explosion was addition, scientists have used its radiation colossal, being more powerful than all of the to study accelerated aging and radiation high explosives used in World Wars I and II damage, and have examined its potential combined1. In an instant, an enormous for medical treatments, although not number of neutrons (around 1024–1025 cm–2, commercially7. Outside of basic research, ref. 2) blasted into the uranium atoms used einsteinium has no practical use. So although in the bomb. Some of these atoms captured its name lends it a familiarity, most of us KEYSTONE-FRANCE / GAMMA-KEYSTONE / GETTY IMAGES / GAMMA-KEYSTONE KEYSTONE-FRANCE 15 neutrons each — resulting in very will never come across even a single atom of heavy uranium isotopes — before rapidly Einstein warns of the dangers of developing the einsteinium in our lifetimes.
    [Show full text]
  • Periodic Table of the Elements American Spellings Hydrogen Helium 1 2
    Periodic Table of the Elements American Spellings hydrogen helium 1 2 H He 1.00794 Key: 4.002602 lithium beryllium Element Name boron carbon nitrogen oxygen fluorine neon 3 4 Atomic # 5 6 7 8 9 10 Li Be Atomic Symbol B C N O F Ne 6.941 9.012182 10.811 12.0107 14.00674 15.9994 18.9984 20.1797 Atomic Mass sodium magnesium aluminum silicon phosphorus sulfur chlorine argon 11 12 13 14 15 16 17 18 Na Mg Al Si P S Cl Ar 22.98977 24.3050 26.981538 28.0855 30.97376 32.065 35.453 39.984 potassium calcium scandium titanium vanadium chromium manganese iron cobalt nickel copper zinc gallium germanium arsenic selenium bromine krypton 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 K Ca Sc Ti V Cr Mn Fe Co Ni Cu Zn Ga Ge As Se Br Kr 39.0983 40.078 44.95591 47.867 50.9415 51.9961 54.93805 55.845 58.9332 58.6934 63.546 65.409 69.723 72.64 74.9216 78.96 79.904 83.798 rubidium strontium yttrium zirconium niobium molybdenu technetium ruthenium rhodium palladium silver cadmium indium tin antimony tellurium iodine xenon 37 38 39 40 41 m 43 44 45 46 47 48 49 50 51 52 53 54 Rb Sr Y Zr Nb 42 Tc Ru Rh Pd Ag Cd In Sn Sb Te I Xe 85.4678 87.62 88.90585 91.225 92.90638 Mo [98] 101.07 102.9055 106.42 107.8682 112.411 114.818 118.710 121.760 127.60 126.9045 131.293 95.94 cesium barium lutetium hafnium tantalum tungsten rhenium osmium iridium platinum gold mercury thallium lead bismuth polonium astatine radon 55 56 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 Cs Ba Lu Hf Ta W Re Os Ir Pt Au Hg Tl Pb Bi Po At Rn 132.90545 137.327 174.967 178.49 180.9479 183.84
    [Show full text]
  • Atomic Weights of the Elements 2007 (IUPAC Technical Report)*
    Pure Appl. Chem., Vol. 81, No. 11, pp. 2131–2156, 2009. doi:10.1351/PAC-REP-09-08-03 © 2009 IUPAC, Publication date (Web): 18 September 2009 Atomic weights of the elements 2007 (IUPAC Technical Report)* Michael E. Wieser1,‡ and Michael Berglund2 1Department of Physics and Astronomy, University of Calgary, Canada; 2European Commission, Joint Research Centre, Institute for Reference Materials and Measurements (IRMM), Belgium Abstract: The latest evaluation of atomic weight determinations and other cognate data has warranted five changes for the standard atomic weights of the elements, Ar(E), from those published previously in the Table of Atomic Weights 2005. The revised standard atomic weight of nickel, Ar(Ni), is 58.6934(4); zinc, Ar(Zn), is 65.38(2); molybdenum, Ar(Mo), is 95.96(2); ytterbium, Ar(Yb), is 173.054(5); and lutetium, Ar(Lu), is 174.9668(1). Standard atomic weight tables abridged to four and five significant figures were also evaluated. The Commission-recommended value for the isotope-amount ratio of n(40Ar)/n(36Ar), which is of importance in geochronology and geochemistry, has been changed to 298.56(31) from 296.03(53) based on new measurements. Atmospheric O2 is recognized as an international measurement standard, along with Vienna Standard Mean Ocean Water (VSMOW) and Vienna Pee Dee Belemnite (VPDB) carbonate for measurement and reporting of differences in relative oxygen isotope-amount ratios δ (17O) and δ (18O). Keywords: argon isotopes; half-lives; IUPAC Inorganic Chemistry Division; lutetium; molyb- denum; nickel; oxygen-17; ytterbium; zinc. INTRODUCTION The Commission on Isotopic Abundances and Atomic Weights (CIAAW) met in Pisa, Italy under the chairmanship of Prof.
    [Show full text]