Arsenic properties

That does not make sense because arsenics properties are much more like those of phosphorus and antimony, not like those of aluminum and indium. 

Bromine has a lower electron affinity and electrode potential than chlorine but is still a very reactive element. It combines violently with alkali metals and reacts spontaneously with phosphorus, arsenic and antimony. When heated it reacts with many other elements, including gold, but it does not attack platinum, and silver forms a protective film of silver bromide. Because of the strong oxidising properties, bromine, like fluorine and chlorine, tends to form compounds with the electropositive element in a high oxidation state. 

Both chloramine-T and dichloramine-T have marked antiseptic properties, chloramine-T being most frequently used because of its solubility in water. Aqueous solutions of chloramine-T can be used either for external application, or for internal application to the mouth, throat, etc, as chloramine-T in moderate quantities is non-toxic its aqueous solution can also be effectively used when the skin has come in contact with many of the vesicant liquid poison-gases, as the latter are frequently organic sulphur or arsenic derivatives which combine with or are oxidised by chloramine-T and are thus rendered harmless. 

Thousands of compounds of the actinide elements have been prepared, and the properties of some of the important binary compounds are summarized in Table 8 (13,17,18,22). The binary compounds with carbon, boron, nitrogen, siUcon, and sulfur are not included these are of interest, however, because of their stabiUty at high temperatures. A large number of ternary compounds, including numerous oxyhaUdes, and more compHcated compounds have been synthesized and characterized. These include many intermediate (nonstoichiometric) oxides, and besides the nitrates, sulfates, peroxides, and carbonates, compounds such as phosphates, arsenates, cyanides, cyanates, thiocyanates, selenocyanates, sulfites, selenates, selenites, teUurates, tellurites, selenides, and teUurides. 

Helium-3 [14762-55-1], He, has been known as a stable isotope since the middle 1930s and it was suspected that its properties were markedly different from the common isotope, helium-4. The development of nuclear fusion devices in the 1950s yielded workable quantities of pure helium-3 as a decay product from the large tritium inventory implicit in maintaining an arsenal of fusion weapons (see Deuterium AND TRITIUM) Helium-3 is one of the very few stable materials where the only practical source is nuclear transmutation. The chronology of the isolation of the other stable isotopes of the hehum-group gases has been summarized (4). 

A. H. Landrock, Polyurethane Foams Technology Properties and Applications, Report 37, Plastic Technical Evaluation Center, Picatiuny Arsenal, Dover, N.J., 1969. 

Excellent antifriction properties and good hardness (qv) make lead—antimony—tin alloys suitable for journal bearings. The alloys contain 9—15 wt % antimony and 1—20 wt % tin and may also contain copper and arsenic, which improve compression, fatigue, and creep strength important in bearings. Lead—antimony—tin bearing alloys are Hsted in ASTM B23-92 (7). 

Rea.ctivity ofLea.d—Ca.lcium Alloys. Precise control of the calcium content is required to control the grain stmcture, corrosion resistance, and mechanical properties of lead—calcium alloys. Calcium reacts readily with air and other elements such as antimony, arsenic, and sulfur to produce oxides or intermetaUic compounds (see Calciumand calciumalloys). In these reactions, calcium is lost and suspended soHds reduce fluidity and castibiUty. The very thin grids that are required for automotive batteries are difficult to cast from lead—calcium alloys. 

Tia is also used as an ahoyiag element ia lead—antimony alloys to improve fluidity and to prevent drossiag, ia lead—calcium alloys to improve mechanical properties and enhance electrochemical performance, ia lead—arsenic alloys to maintain a stable composition, and as an additive to low melting alloys. 

Lead—tin (1.8—2.5 wt %) is used both as a cable sheathing ahoy (BS 801 ahoy A and DIN 17640) and as a battery connector ahoy ia sealed lead—calcium—tin batteries (15). Tia is generahy added to lead—arsenic cable ahoys ia smah amounts. The arsenic ahoys have excehent creep resistance and mechanical properties, but are unstable and lose arsenic readily by oxidation. The addition of smah amounts of tin (0.10—0.20 wt %) eliminates arsenic loss. Lead ahoys having 0.4 wt % tin and 0.15 % cadmium, which are used for cable sheathing, do not age harden, show excehent corrosion and creep resistance, and are very ductile. 

Impurities in cmde metal can occur as other metals or nonmetals, either dissolved or in some occluded form. Normally, impurities are detrimental, making the metal less useful and less valuable. Sometimes, as in the case of copper, extremely small impurity concentrations, eg, arsenic, can impart a harmful effect on a given physical property, eg, electrical conductivity. On the other hand, impurities may have commercial value. For example, gold, silver, platinum, and palladium, associated with copper, each has value. In the latter situation, the purity of the metal is usually improved by some refining technique, thereby achieving some value-added and by-product credit. 

Arsenic. Arsenic is under consideration for inclusion as an essential element. No clear role has been estabHshed, but aresenic, long thought to be a poison, may be involved in methylation of macromolecules and as an effector of methionine metaboHsm (158,160). Most research has focused on the toxicity or pharmaceutical properties of arsenic (158). 

Shale oil contains large quantities of olefinic hydrocarbons (see Table 8), which cause gumming and constitute an increased hydrogen requirement for upgrading. Properties for cmde shale oil are compared with petroleum cmde in Table 10. High pour points prevent pipeline transportation of the cmde shale oil (see Pipelines). Arsenic and iron can cause catalyst poisoning. 

Physical properties of a-crystaUine metallic arsenic are given in Table 1. The properties of P-arsenic are not completely defined. The density of P-arsenic is 4700 kg/m it transforms from the amorphous to the crystalline form at 280 °C and the electrical resistivity is reported to be 107 H-cm. 

Arsenic added ia amounts of 0.1—3% improves the properties of lead-base babbitt alloys used for beatings (see Bearing materials). Arsenic (up to 0.75%), has been added to type metal to increase hardness and castabiUty (21). Addition of arsenic (0.1%) produces a desirable fine-grain effect in electrotype metal without appreciably affecting the hardness or ductihty. Arsenic (0.5—2%) improves the sphericity of lead ammunition. Automotive body solder of the composition 92% Pb, 5.0% Sb, and 2.5% Sn, contains 0.50% arsenic (see Solders and brazing alloys). 

Arsenic Halides. Arsenic forms a complete series of trihaUdes, but arsenic pentafluoride is the only well-known simple pentahaUde. AH of the arsenic haUdes, the physical properties of which are given in Table 2, are covalent compounds that hydrolyze in the presence of water. The trihaUdes form pyramidal molecules similar to the trivalent phosphoms analogues and may be prepared by direct combination of the elements. 

Arsenic Sulfides. The physical properties of the common arsenic sulfides are given in Table 3. Numerous arsenic sulfides have been reported as well as compounds containing the As2S" 4 cation [77825-63-9] (24). 

Copper. The physical properties of pure copper are given in Table 11. The mechanical properties of pure copper are essentially the same as those for ClOl and CllO. The coppers represent a series of alloys ranging from the commercially pure copper, ClOl, to the dispersion hardened alloy C157. The difference within this series is the specification of small additions of phosphoms, arsenic, cadmium, tellurium, sulfur, zirconium, as well as oxygen. To be classified as one of the coppers, the alloy must contain at least 99.3% copper. 

Alloys of antimony, tin, and arsenic offer hmited improvement in mechanical properties, but the usefulness of lead is limited primarily because of its poor structural qualities. It has a low melting point and a high coefficient of expansion, and it is a veiy ductile material that will creep under a tensile stress as low as 1 MPa (145 IbFin"). 

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