Bismuth atomic properties

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. 

Both nitrogen and bismuth are members of Group 5A(15). Which is more metallic Explain your answer in terms of atomic properties. 

This review covers 71-excessive five-membered ring systems containing one arsenic, antimony, or bismuth atom within the ring. Their benzo-, dibenzo-, unsaturated, partially unsaturated, and saturated analogues are also covered. These heteroatoms can have expanded valence shells and thus different coordination numbers (CN) are included as well. Although not strictly covered in this Chapter, mention is made of systems containing one of the above heteroatoms with another atom within the ring, but usually to show an important property of the system. 

From the neutron diffraction study the site occupancies of the ytterbium, platinum, and bismuth atoms are clear (Robinson et al. 1994). Since these heavy atoms differ only by few electrons, it is difficult to assign the correct sites only on the basis of X-ray powder diffraction data. Another important feature concerns the wet chemical analysis. Since all crystals of YbPtBi were grown from a bismuth flux, elemental bismuth occurs as an impurity phase in all samples. An amount of 8.1wt.% was detected in a neutron diffraction experiment. In view of this impurity, the absolute values of all physical property measurements should be discussed with caution. 

The phase transiton from a paraelectric to a ferroelectric state, most characteristic for the SbSI type compounds, has been extensively studied for SbSI, because of its importance with respect to the physical properties of this compound (e.g., J53, 173-177, 184, 257). The first-order transition is accompanied by a small shift of the atomic parameters and loss of the center of symmetry, and is most probably of a displacement nature. The true structure of Sb4S5Cl2 106), Bi4S5Cl2 194), and SbTel 108,403) is still unknown. In contrast to the sulfides and selenides of bismuth, BiTeBr 108) and BiTel (JOS, 390) exhibit a layer structure similar to that of the Cdl2 structure, if the difference between Te, Br, and I (see Fig. 36) is ignored. 

There are many organometallic compounds of arsenic, antimony, and bismuth known that constitute series having chemical properties that differ markedly. These compounds generally decrease in stability in the order As > Sb > Bi, which agrees with the increasing difference in size of the atoms and carbon atoms. Arsenic compounds include both aliphatic derivatives and heterocycles such as arsabenzene,... 

All elements, by definition, have a unique proton number, but some also have a unique number of neutrons (at least, in naturally occurring forms) and therefore a unique atomic weight - examples are gold (Au Z = 79, N = 118, giving A =197), bismuth (Bi Z = 83, N = 126, A = 209), and at the lighter end of the scale, fluorine (F Z = 9, N = 10, A = 19) and sodium (Na Z = 11, N= 12, A = 23). Such behavior is, however, rare in the periodic table, where the vast majority of natural stable elements can exist with two or more different neutron numbers in their nucleus. These are termed isotopes. Isotopes of the same element have the same number of protons in their nucleus (and hence orbital electrons, and hence chemical properties), but... 

The ylides and imides are present as monomers, and the bismuth center adopts a distorted tetrahedral geometry. In contrast, the structural properties of the bismuth oxides vary widely depending on the aryl ligands attached to the bismuth center the oxides exist as hydrates, dimers, or polymers in solution and in the solid state. X-ray structural analysis of an oxide dimer revealed that the bismuth center has a distorted, trigonal bipyramidal geometry with the two oxygen atoms at the apical and equatorial positions [47, 48]. 

German team of physicists at GSI, Darmstadt, Germany Highly unstable and presumed to be a metal, but little else is known of its properties produced by bombarding bismuth with accelerated nickel atoms. 

Uranium-238 emits an alpha particle to become an isotope of thorium. This unstable element emits a beta particle to become the element now known as Protactinium (Pa), which then emits another beta particle to become an isotope of uranium. This chain proceeds through another isotope of thorium, through radium, radon, polonium, bismuth, thallium and lead. The final product is lead-206. The series that starts with thorium-232 ends with lead-208. Soddy was able to isolate the different lead isotopes in high enough purity to demonstrate using chemical techniques that the atomic weights of two samples of lead with identical chemical and spectroscopic properties had different atomic weights. The final picture of these elements reveals that there are several isotopes for each of them. 

In the latter, the valency angles must be about 100°, so the layers cannot be flat. Their shape is obtained if, in Figure 38, the atoms shown with the clear circles are displaced somewhat below the plane of the paper and the shaded ones similarly, above it. If the layers formed in this way are then arranged on top of one another, the crystal structure of the elements arsenic, antimony and bismuth are obtained in their normal forms in which they have metallic properties. There also exists a modification of phosphorus with a similar structure. In addition, there are other forms of arsenic and antimony, the properties of which correspond to those of yellow phosphorus these forms contain molecules p As4 and Sb4. 

As a catalyst for propylene oxidation, Bi203 itself has fairly low activity and yields primarily the products of complete oxidation. Pure molybdenum trioxide has an even lower activity, but is fairly selective. In combination, however, remarkable activity and selectivity for propylene oxidation is obtained. Although industrial catalysts contain silica and phosphate as well as Bi203 and Mo03, many fundamental studies have employed catalysts containing only bismuth and molybdenum oxides in an attempt to determine the structure of the catalytically active phase. As a result of such studies, it is now known that bismuth molybdate catalysts display their superior properties only if the catalyst composition lies within the composition range of Bi/Mo = f to f (atomic ratio). 

Some of the schemes in Table 6.6 may be difficult to distinguish. Thus NH4 could be described either by (4) or (10), and molecules such as X3PO are best described (as discussed in Section 6.1) in terms of resonance between structures (4) and a triple-bonded structure X3P b" (5 however, the properties of the molecule are consistent with a P-O bond order of about two, consistent with scheme (9). Schemes (9) and (11)—(13) require nd orbitals on the Group 15 atom and are found only for the heavier atoms, from P downwards. Arsenic and bismuth show some reluctance to adopt (9), (11) and (12), probably because their ns electrons are quite strongly bound as inert pairs . Thus AsC15, which defied preparative attempts for many decades, is stable only at low temperatures, and H3As03 has a different structure from that of H3P03 ... 

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