Elements semimetallic

The element is a steel gray, very brittle, crystalline, semimetallic solid it tarnishes in air, and when heated is rapidly oxidized to arsenous oxide with the odor of garlic. Arsenic and its compounds are poisonous. 

For the same reasons, data on single-crystal faces for metals such as Zn, Sb, Bi, Sn, and Cd have not been plotted in Fig. 15. In order to indicate the probable position of d-metal surfaces, the line described by Eq. (64) has also been drawn in Fig. 15. It is interesting that all the points for sd-metals fall between the sp- and the d-metal groups. The crystal face specificities of Eas0 for Sb and Bi are complicated by their semimetallic nature. In any case, no data on 0 exist for a series of faces of these elements (only electrochemical work functions are available).28,864... 

Tile element uranium also exhibits a formal oxidation number of (II) in a few solid compounds, semimetallic in nature, such as UO and US. No simple uranium ions of oxidation state (II) are known in solution. 

The berkelium monopnictides have been prepared on the multimicrogram scale by direct combination of the elements (138). In all cases, the lattice constants of the NaCl-type cubic structures were smaller than those of the corresponding curium monopnictides but comparable to those of the corresponding terbium compounds. This supports the semimetallic classification for these compounds. One additional report of BkN has appeared (139). The lattice parameter derived from the sample exhibiting a single phase was 0.5010 0.0004 nm, whereas that extracted from the mixed-phase sample of BkN resulting from incomplete conversion of a hydride was 0.4948 0.0003 nm. Clearly, additional samples of BkN should be prepared to establish more firmly its lattice constant. 

Other methides are the cubic ternary carbides of the type A3MC31 where A is mostly a rare earth or transition element (e.g., Sc, Y, La—Na, Gd—Lu) and M is a metallic or semimetallic main group element (e.g., Al, Ge, In, Tl, Sn, Pb). These perovskite carbides are typically hydrolyzed by dilute HC1 to give —84-97 (wt-%) methane and 3-16% saturated and unsaturated higher hydrocarbons. 

The one form of tellurium is silvery-white, semimetallic, and isomorphous with grey Se. Like the latter it is virtually insoluble in all liquids except those with which it reacts. Even though Te8 rings are not found in elemental tellurium, they do occur in the compound C Te, 5 which also contains unusual planar nets of Te atoms. 

It may seem surprising that carbon, with its vast range of literally millions of compounds, is not the most abundant element in this group. By far the most abundant of Group 14 (IVA) elements on Earth is silicon, which comprises 27% of the Earth s crust (by mass) and is second in abundance (after oxygen) carbon is only 17th in abundance. Silicon, with its semimetallic properties, is of enormous importance in the semiconductor industry, with wide applications in such fields as computers and solar energy collection. 

In its elemental form, arsenic is an odorless, tasteless semimetallic compound, which appears steel gray in color, is brittle and is a crystalline solid. The symbol is As the atomic number is 33. Arsenic compounds were mined by the early Chinese, Greek, and Egyptian... 

The chemistry of imidodiphosph(in)ato ligands and their metal complexes, or some of its particular aspects, has been reviewed more or less comprehensively, at various stages and covers almost all metallic and semimetallic elements of the periodic table.12-21... 

Arsenic compounds were known in antiquity, and the name is derived from the Greek arsenikon and the Latin arsenicum. Elemental arsenic may have been discovered by Albertus Magnus in 1250, but this is unclear. In was Johann Schroeder in 1649 who published two methods for producing arsenic, after isolating elemental arsenic. Arsenic was historically used in medicines and was developed as a treatment for syphilis. Its high level of toxicity led to its use as an insecticide. Since arsenic is a semimetallic element, it has properties that make it useful for modern electronics such as transistors. 

At present a large variety of solid compounds are called Zintl phases. The name Zintl phase was introduced by Laves According to Laves, Zintl phases are those intermetallic compounds which crystallize in typical non-metal crystal structures. For these compounds one expects an ionic contribution to the chemical bond. This definition has been extended to a large number of solid compounds formed by alkali or alkaline earth metals with metallic or semimetallic elements of the fourth, fifth and partly third group of the Periodic Table for which common structural and bonding properties have been found. The crystal structures and chemical properties of these compounds have been studied extensively . ... 

Actinide chalcogenides can be obtained for instance by reaction of the elements, and thermal stability decreases S > Se > Te. Those of a given actinide differ from those of another in much the same way as do the oxides. Nonstoichiometry is again prevalent and, where the actinide appears to have an uncharacteristically low oxidation state, semimetallic behaviour is usually observed. 

Sulfides, Phosphides and Similar Compounds. Direct interaction of the metal and other elements such as S, Se, Te, P, As, Bi, Sn or Pb under selected conditions produces dark, often semimetallic, solids that are resistent to acids other than nitric. These products may be stoichiometric compounds and/or non-stoichiometric phases depending upon the conditions of preparation. 

Gschneidner, K.A., Jr., 1964, Physical Properties and Interrelationships of Metallic and Semimetallic Elements, in Seitz, F. and D. Turnbull, eds.. Solid State Physics, Vol. 16 (Academic Press, New York 1%4) p. 275. 

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