Elemental bismuth

Bismuth, Bi, the 83rd element of the periodic table is the most metallic and the least abundant of the elements in the nitrogen family (group 15). It has an atomic mass of 208.980 and a ground state electronic configuration of [Xe] 4f 5d %s 6p. The bismuth atom usually utilizes the three 6p electrons in bond formation and retains the two 6s electrons as an inert pair, hence the oxidation state -1-3 exhibited by bismuth in the vast majority of its compounds. However, a variety of organobismuth compounds can contain the element in the -1-5 oxidation state. Coordination numbers are 2, 3,4, 5 and 6. Bismuth not only has metallic characteristics but also exhibits many properties similar to those of semiconductors and insulators. Consequently, it is often classified as a semi-metal or metalloid. Bismuth compounds are usually colorless unless the metal is bound to a chromophore. 

Natural bismuth consists of only one stable isotope, ° Bi, with a nuclear spin of —9/2, but there are many isotopes which exhibit a wide range of half-lives, from Bi of t /2 1.5 s up to Bi of t /21 min. Natural isotope Bi decays by a-emission with a half-life of more than 10years to form T1. The second and third stable isotopes, Bi and Bi, decay by electron capture with a half-life of 3.86 X 10 and 32.2 years, respectively. Isotopes with a 

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Nitrogen is unusual in forming so many oxides. The acidity of the Group V oxides falls from phosphorus, whose oxides are acidic, through arsenic and antimony whose oxides are amphoteric, to the basic oxide ofbismuth. This change is in accordance with the change from the non-metallic element, phosphorus, to the essentially metallic element, bismuth. The +5 oxides are found, in each case, to be more acidic than the corresponding + 3 oxides. 

The element bismuth [7440-69-9] Bi, found ia Group 15 (VA) of the Periodic Table, has at no. 83, at wt 208.98. Its valences are +5 and +3. Bismuth is a silvery metal having a high metallic luster and exhibits a slightly pink tinge on a cleanly broken surface. The metal itself is britde ia nature and easily broken. 

Bismuth is the fifth element in the nitrogen group, and its properties are the most metal-like of the five. Elemental bismuth is a heavy, brittle, hard metal that can be polished to a bright gray-white coat with a pinkish hue. It is not found in this state very often because it is more likely to be combined with other metals and minerals, such as tin, lead, iron and cadmium. These are mixtures with low melting points, making them useful in fire-detection devices. 

Ununpentium is also known as eka-bismuth because it is homologous to the element bismuth located at the bottom of Group 15 (VA). Its melting point, boihng point, and density are unknown as are many of its other properties. Several isotopes of element 115 were produced by the nuclear reaction that bombarded calcium into a target americium, resulting in the fusion of the calcium nuclei with the americium nuclei to form isotopes of element 115 (ununpentium). 

Bismuth, which has been known since ancient times, was often confused with lead and tin. Basilius Valentinus described some of its uses in 1450, but it was in 1753 that bismuth was shown by Claude Francois Geoffroy to be a distinct element. Bismuth occurs freely in nature and in such minerals as bismuthinite (Bi2S3), bismite (Bi203), and bismutite KBiObCO i. ... 

Generally, die chemical behavior of bismuth parallels that of arsenic and antimony, but bismuth is the most metallic of the group. Bismuth is not soluble in cold H2S04 or cold HC1, but is attacked by these acids when hot and also hy cold aqua regia. Elemental bismuth is not attacked by cold alkalies. The metal is soluble in HNO3 and forms nitrates. When heated with chlorine, bismuth yields a chloride. 

Reaction of elemental bismuth with the halogens at elevated temperatmes leads to the production of BiX3. Properties of the trihalides are summarized in Table 2. Bismnth is first oxidized by P2(g) to BiFs, with conversion to BiFs occming above 600 °C. The latter is the only known homoleptic bismnth(V) halide, although organic derivatives of the form... 

The two heaviest members of Group 6A can lose electrons to form cations. Although they do not lose all six valence electrons because of the high energies that would be required, tellurium and polonium appear to exhibit some chemistry involving their 4+ cations. However, the chemistry of these Group 6A cations is much more limited than that of the Group 5A elements bismuth and antimony. 

Interestingly, the product is head-to-head , i.e. it has one new C—C and Sb—Sb bond, as opposed to two new C—Sb bonds. Assume we were convinced of the more or less invariance of the Sb—Sb bond enthalpy and that we had a reliable value for the —Sb bond enthalpy (say from a more trustworthy measurement of the enthalpy of formation of triphenylstibine ). With judicious use of Benson increments and strain corrections, one could thus estimate the enthalpy of formation of the dimer, and accordingly derive a trustworthy value for the monomer. We would then have a handle on the aromaticity of antimonin. The enthalpy of reaction of bismin, CjHjBi, to form the analogous dimer has likewise been derived to be — 50kJmoCL However, this does not particularly help us since elemental bismuth is metallic, i.e. it is illogical to consider that Bi (s) is held together by covalent Bi—Bi bonds. 

Bismuth is a rather rare element in the earth s crust, but its oxides and sulfides appear at sufficient concentrations as impurities in lead and copper ores to make its recovery from these sources practical. Annual production of bismuth amounts to several million kilograms worldwide. Although elemental bismuth is a metal, its electrical conductivity is quite poor and it is relatively brittle. The major uses of bismuth arise from its low melting point (271.3°C) and the even lower melting points of its alloys, which range down to 47°C. These alloys are used as temperature sensors in fire detectors and automatic sprinkler systems because, in case of... 

The resins Chelex-100 and Permutit S 1005 are claimed to completely retain the heavy elements bismuth and thorium from sea water. These elements are quantitatively removed from the resins by elution with 2 N mineral acids 56). 

BiHs is unstable above -45 °C, yielding hydrogen gas and elemental bismuth. The original preparation was reported in 1961, but it was not until 2002 that this procedure was repeated and yielded enough BiHs to do spectroscopy on ... 

Elemental bismuth is inert in dry air at room temperature, but oxidizes slowly to become covered with a thin film of the oxide, which gives it a beautiful multi-colored luster. Above its melting point, it oxidizes rapidly to form an oxide film. At red heat in air, it bums with a bluish flame to give a yellow fume of bismuth oxide (BiiOj). It can also be attacked by super-heated water vapor to form the yellow oxide. Heating with sulfur produces bismuth sulfide Bi2S3 as a dark brown to grayish black solid. 

The reaction of tetramethyldibismuthine with iodine gives all possible iodo(methyl)bismuthines as well as elemental bismuth [830M1859]. Similarly, tetraphenyldibismuthine reacts with iodine to give iododiphenylbis-muthine as the single product [84JCS(D)2365]. 

Harkins2 points out that of the known elements bismuth has the highest odd atomic number (83) except the radioactive descendants of uranium or thorium, whose half life periods, so far as they are known, are very short. The even atomic numbers from 82 to 92 are represented fully and many of these elements are very stable. It seems reasonable, therefore, to conclude that the electron systems required for the atomic numbers 85 and 87 are unstable and may not be able to exist at all. 

Bismuth ore, often called bismuth glance, contains an ionic compound consisting of the elements bismuth and sulfur. A sample of the pure compound is found to contain 32.516 g Bi and 7.484 g S. What is the empirical formula for this compound What is its name ... 

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