Element chemistry

The 20 largest rivers on Earth carry about 40% of the total continental runoff, with the Amazon alone accounting for about 15% of the total. These rivers give the best indication of global average riverwater chemical composition, which can be compared with average continental crust composition (Table 5.1). Three features stand out from this comparison  

1 Four metals dominate the dissolved chemistry of freshwater, all present as simple cations (Ca2+, Na+, K+ and Mg2 ). 

3 The dissolved ionic composition of freshwater is radically different from continental crust, despite the fact that all of the cations in riverwater, with the exception of some of the sodium and chloride (see Section 5.3), are derived from weathering processes. 

Although it is not meaningful to derive a single global average composition for groundwater—because of the marked differences in aquifer rocks—it is nonetheless true that most groundwaters share the three features listed above for riverwater (see Table 5.3). 

The difference between crustal and dissolved riverwater composition is particularly marked for aluminium and iron relative to other metals (Table 5.1). This difference results from the way specific metal ions react with water. 

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Since about 1970 there has been very little activity in the whole field of aryl-element chemistry as fas as arenediazonium ions are involved. The activity on As- and Sb-organic compounds early in this century was probably stimulated by the discovery of Salvarsan (3,3 -diamino-4-4 -dihydroxy-arsenobenzene) by Paul Ehrlich in 1909. In spite of the epoch-making success of this first chemotherapeutic drug, it... 

Fergusson, J. E. The Heavy Elements Chemistry, Environmental Impact and... 

Lewis, W. M. Jr., Hamilton, S. K., Jones, S. L. and Runnels, D. D. (1987). Major element chemistry, weathering, and element yields for the Caura River drainage, Venezuela. Biogeochemistry 4,159-181. 

He is a recognized expert in solid state and materials chemistry and environmental chemistry. He has active programs in solid state f-element chemistry and nanomaterials science. His current research interests include heavy metal detection and remediation in aqueous environments, ferroelectric nanomaterials, actinide and rare-earth metal sohd slate chemistry, and nuclear non-proliferation. He currently maintains a collaboration in nuclear materials with Los Alamos National Laboratory and a collaboration in peaceful materials science development with the Russian Federal Nuclear Center - VNIIEF, Sarov, Russia, U.S. State Department projects. He has published over 100 peer-reviewed journal articles, book chapters, and reviews, while presenting over 130 international and national invited lectures on his area of chemistry. Dr. Dorhout currently serves as Vice Provost for Graduate Studies and Assistant Vice President for research. He has also served as the Interim Executive Director for the Office of International Programs and as Associate Dean for Research and Graduate Education for the College of Natural Sciences at Colorado State University. 

Hess, B.A. (ed.) (2003) Relativistic Effects in Heavy-Element Chemistry and Physics, John Wiley Sons, Ltd, Chichester. 

Numerous studies on lavas from the Hawaiian Islands have shown that over the lifespan of a volcano, the major- and trace-element chemistry of the erupted basalts vary significantly and systematically (MacDonald and Katsura 1964 Chen and Frey 1985). This variation is believed to be the result of movement of the Pacific plate, over the... 

Brenan JM, Shaw HF, Ryerson FJ, Phinney DL (1995) Mineral-aqueous fluid partitioning of trace elements at 900 °C and 2.0 GPa constraints on the trace element chemistry of mantle and deep crastal fluids. Geochim Cosmochim Acta 59 3331-3350... 

Plank T, Langmuir CH (1988) An evaluation of the global variations in the major element chemistry of arc basalts. Earth Planet Sci Lett 90 349-370... 

Cornell University, Ithaca, NY Characterizing trace element chemistry in... 

Submicrogram Methods used in Studies of the Synthetic Elements. Chemistry Division Annual Report I960. Report UCRL-9566, S. 210ff. (Febr. 1961). 

Sposito G., LeVesque C.S., LeClaire J.P., Chang A.C. Trace elements chemistry in arid-zone field soils amended with sewage sludge III. Effect of the time on the extraction of trace metals. Soil Sci Soc Am J 1983 47 898-902. 

Schroder, D. Diefenbach, M. Schwarz, H. Schier, A. Schmidbaur, H. In Relativistic Effects in Heavy-element Chemistry and Physics ... 

The aim of this review is to focus on the hydrogen bonding, the acidity and basicity, complexing as well as some aspects of computational chemistry concerning the organo-element chemistry of germanium, tin and lead. This chapter is not exhaustive in scope, but rather consists of surveys of the most recent decade of work in this still developing area. This chapter emphasizes the synthesis, reactions and molecular structures of the class of... 

Both direct and indirect methods were tested in the Lisbon area. Direct methods include the assessment of hydrocarbon compositional signatures in surface soils, outcrop fracture-fill soils and mosses, and 6-ft (2 m) deep free-gas samples. Indirect methods pertain to the major and trace element chemistry of soils to look for alteration effects resulting from hydrocarbon microseepage. 

Horowitz, A.J. 1991. A primer on Sediment -trace element chemistry. Lewis Publishers Ltd., Chelsea, Ml. 

We have made one rather obvious omission from our descriptions of molecule electronic structure - the structure of transition-metal ions. This is deliberate since, in spite of the well-developed theories of the electronic spectra (U.V., photo-electron) of these compounds, it is still true to say that there is no theory of the bonding in this important class of molecules. The question of the localised or de-localised nature of the electronic structure of the bonds in these systems has not really been solved historically, there has been some skirmishing about the superiority of the MO or VB methods but the nature of the valence in these molecules has received a disproportionately small amount of attention. Thus any attempt to develop a GHO basis for transition-metal compounds is perhaps premature until more experience has been gained with typical element chemistry. 

The replacement of the diazonio group by metals and related transition elements was investigated intensively until the mid-20th century, particularly by Nesmeyanov and coworkers (reviews173). Most intensively studied were mercury-de-diazoniations. Since about 1970 there has been very little activity in the whole field of aryl-element chemistry as far as arenediazonium salts are involved. This decrease is probably due to the lack of interest for technological purposes, and to the environmental problem, which the synthesis and the use of the compounds cause. 

Molecules are described in terms of a Hamiltonian operator that accounts for the movement of the electrons and the nuclei in a molecule, and the electrostatic interactions among the electrons and the electrons and the nuclei. Unlike the theory of the nucleus, there are no unknown potentials in the Hamiltonian for molecules. Although there are some subtleties, for all practical purposes, this includes relativistic corrections, [2] although for much of light-element chemistry those effects are... 

Leaching of chemicals from complex materials or matrices is a complicated phenomenon in which many factors may influence the release of the specific organic compounds and inorganic ions. Important factors include major element chemistry, pH, redox, complexation, liquid to solid ratio, contact time, and biological activity. To describe fully the leaching of SWMs/COMs under field conditions, a battery of leaching tests was specifically designed to simulate various physical and chemical release mechanisms. 

Falkner KK, Church M, Measures Cl, LeBaron G, Thouron D, Jeandel C, Stordal MC, Gill GA, Mortlock R, Froelich P, Chan LH (1997) Minor and trace element chemistry of Lake Baikal, its tributaries, and surrounding hot springs. Limnol Oceanogr 42 329-345... 

Michael PJ, Cornell WC (1998) The induence of spreading rate and magma supply on crystallization and assimilation beneath mid-ocean ridges evidence from chlorine and major element chemistry of MORB. 

Welz, B., Schubert-Jacobs, M., Schlemmer, G. and Sperling, M., Lecture at 5th International Workshop Trace Elemental Chemistry in Medicine and Biology, 1988, Neuherberg, Germany. 

In chapter 2, M. Tanaka summarizes the current state of the art of the homogeneous catalysis of H-P bond addition reactions, thus showing that as hydro-silylation and hydroboration, the H-P addition reactions are among the indispensable modern synthetic reactions needed by researchers in organic and main group element chemistry. 

Ottonello G., Piccardo G. B. and Ernst W. G. (1979). Petrogenesis of some Ligurian peridotites, II Rare earth element chemistry. Geochim. Cosmochim. Acta, 43 1273-1284. 

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