Nickel chemical properties

Nickel occurs in the first transition row in Group 10 (VIIIB) of the Periodic Table. Some physical properties are given in Table 1 (1 4). Nickel is a high melting point element having a ductile crystal stmcture. Its chemical properties allow it to be combined with other elements to form many alloys. 

However, Pauli s Nobel Prize-winning work did not provide a solution to the question which I shall call the closing of the periods —that is why the periods end, in the sense of achieving a full-shell configuration, at atomic numbers 2,10, 18, 36, 54, and so forth. This is a separate question from the closing of the shells. For example, if the shells were to fill sequentially, Pauli s scheme would predict that the second period should end with element number 28 or nickel, which of course it does not. Now, this feature is important in chemical education since it implies that quantum mechanics cannot strictly predict where chemical properties recur in the periodic table. It would seem that quantum mechanics does not fully explain the single most important aspect of the periodic table as far as general chemistry is concerned. 

Nickel is a malleable, ductile, tenacious, slightly magnetic, silvery white metal, which conducts heat and electricity fairly well. It is ferromagnetic at ordinary temperatures but becomes paramagnetic at elevated temperatures. Nickel is closely related in chemical properties to iron and cobalt. While sulphidic sources of nickel account for the world s major nickel supplies, it may be pointed out that lateritic nickel deposits (which essentially constitute an oxidic source of the metal) are more extensive than the sulphidic sources. 

The chemical properties of copper, lead, lead-zinc, and zinc slags are essentially as ferrous silicates, whereas nickel slags are primarily calcium/magnesium silicates. Table 4.13 lists typical chemical compositions of these slags. 

Structural models, which are synthesized to imitate features of the proposed structure of the active site. These may be used to demonstrate the chemical conditions, which allow such structures to exist, to investigate their chemical properties and to give a better understanding of the spectroscopic characteristics of the native proteins. Examples of these include the mixed carbonyl/cyano complexes of iron, used to verify the infrared spectra to the hydrogenases (Fig 7.4) (Lai et al. 1998) and the nickel-thiolate complexes which have low redox potentials like the hydrogenases (Franolic et al. 1992). 

These experts collectively have knowledge of nickel s physical and chemical properties, toxicokinetics, key health end points, mechanisms of action, human and animal exposure, and quantification of risk to humans. All reviewers were selected in conformity with the conditions for peer review specified in Section 104(i)(13) of the Comprehensive Environmental Response, Compensation, and Liability Act, as amended. 

Data on the chemical properties of nickel and some important nickel compounds are shown in Table 3-2. 

Table 3-2. Physical and Chemical Properties of Nickel and Compounds ... 

Physical and Chemical Properties. Except for differences between black and green nickel oxide, the physical and chemical properties of nickel and its compounds reported in Table 3-2 (HSDB 1996) have been adequately characterized. 

Bioavailability from Environmental Media. The absorption and distribution of nickel as a result of inhalation, ingestion, and dermal exposure are discussed in Sections 2.3.1 and 2.3.2. Quantitative data relating the physical/chemical properties of nickel (e.g., particle size, chemical forms of nickel) with its bioavailability are available for inhaled nickel. In aqueous media, nickel is in the form of the hexahydrate ion, which is poorly absorbed by most living organisms (Sunderman and Oskarsson 1991). Additional studies which examine the absorption of nickel from soil would be useful. 

Jhe distribution of beryllium, boron, titanium, vanadium, chromium, cobalt, nickel, copper, zinc, gallium, germanium, tin, molybdenum, yttrium, and lanthanum in the principal coal-producing beds of the Interior Province has been studied by the U. S. Geological Survey. Data, methods of sampling, and analyses are discussed by Zubovic and others (II, 12). This chapter discusses the occurrence of 13 of these elements with respect to geological and geochemical environments of coal deposition and chemical properties of the elements. Zinc and tin are not included in this study because they were detected in only a few samples. 

Feolite catalysts modified by transition metals are interesting and difficult subjects to study. In one of the first studies of zeolites as catalysts, Rabo and co-workers (1) used a zeolite catalyst containing 0.5% platinum for isomerization of n-paraffins. In this reaction the metal-zeolite system acted as a typical representative of the bifunctional catalysts. Studies of zeolites modified by transition metals ( 2, 3, Jf) showed that their polyfunctional properties are determined by the structural and chemical properties of the zeolite and by the state of the metal in it. In this paper we discuss new data on the metal state after reduction as well as the catalytic functions of zeolite catalysts containing nickel and platinum. 

Physico-chemical properties of NbMCM-41 and A1MCM-41 modified with NH/, copper, or nickel... 

Cobalt Compounds. In general the chemical properties arc intermediate between those of iron and nickel. The predominant oxidation stales of cobalt compounds, except for a large class of organumetallie compounds, are 2+ and 3+. Common usage assigns the terms cobaltous and cobaltic. respectively, to these. 

Certain alloys of iron, nickel, and cobalt (Kovar, Fernico, etc.) have thermal expansion curves which nearly match those of borosilicate glasses, and a good bond may be formed between the two. Kovar is similar to carbon steel in its chemical properties. For example, it oxidizes when heated in air and is not wet by mercury. It may be machined, welded, copper brazed, and soft soldered. Silver solders should not be used with Kovar since they may cause embrittlement. At low temperatures Kovar undergoes a phase transformation, and the change in expansion coefficient below this temperature may be sufficient to cause failure of a glass-to-Kovar seal. The transformation temperature usually is below... 

An azo-conjugated catecholato ligand and its nickel complexes, 89 and 90, were synthesized, and their physical and chemical properties were investigated [71]. The complex with one azo-catecholato ligand, 89, shows no obvious photo-response, whereas the compound with two azo-catecholato ligands, 90, causes some photoisomerization. Both complexes show remarkable proton responses. 

Crystal field theory is one of several chemical bonding models and one that is applicable solely to the transition metal and lanthanide elements. The theory, which utilizes thermodynamic data obtained from absorption bands in the visible and near-infrared regions of the electromagnetic spectrum, has met with widespread applications and successful interpretations of diverse physical and chemical properties of elements of the first transition series. These elements comprise scandium, titanium, vanadium, chromium, manganese, iron, cobalt, nickel and copper. The position of the first transition series in the periodic table is shown in fig. 1.1. Transition elements constitute almost forty weight per cent, or eighteen atom per cent, of the Earth (Appendix 1) and occur in most minerals in the Crust, Mantle and Core. As a result, there are many aspects of transition metal geochemistry that are amenable to interpretation by crystal field theory. 

The elements after the rare gas argon all have an inner group of electrons called the argon core and, in addition, outer electrons that determine the chemical properties of the elements. After both the 4s and 3d subsheiis are filled at zinc, the next electron goes into the 4p subshell. The elements from scandium to nickel having incomplete inner (3d) subshells comprise the first row of transition elements. The "discontinuities in the order of... 

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