Polonium species

The average ionic charge of polonium species in chloride solutions was measured using an anion-exchange method. The method is based on measurements of the distribution ratio of polonium at a constant internal chloride ion concentration of the anion-exchanger phase. At TOM hydrochloric acid or sodium chloride solutions at pH of 1.0, tracer concentration of Po(IV) exist in the amionic forms [PoCLi(OH)] and [PoCl4(OH)2].-2... 

Concentrations of Po were measured in the North Atlantic troposphere. Concentrations of Po were measured in rain water, surface seawater, and the marine microlayer. An excess of Po activity was measured in the aerosol relative to what was expected on the basis of Pb and aerosol residence times. In surface seawaters, deficiencies of Po were observed. The mechanism of Po enrichment in the atmospheric aerosol was attributed to possible enrichments from the organic components of the marine microlayer or air sea exchange of organic polonium species. However, no organic compounds of polonium were actually isolated or characterized. 

Table 15.6 Thermodynamic data for polonium species at 25 as derived by Brown (2001).

Liquid tellurium boils at 990 °C to a golden yellow vapor, with density that corresponds to the molecular formula T 2- Likewise, in polonium vapor only P02 species are present. Clearly, the decreasing complexity of the solid state of the three elements Se, Te, and Po, as compared to sulfur, is reflected in the vapor state. 

Within the sulfur sub-group, there are two main types of oxides, the dioxides X 02 (X = S, Se, Te, Po) and the trioxides X Os (X = S, Se, Te). In addition, sulfur also forms disulfur monoxide, S2O. Transient XO species are known in the gaseous phase for S, Se, and Te. Polonium forms a black monoxide PoO. 

There are a series of papers that focus on the behavior of the radon decay products and their interactions with the indoor atmosphere. Previous studies (Goldstein and Hopke, 1983) have elucidated the mechanisms of neutralization of the Po-218 ionic species in air. Wilkening (1987) reviews the physics of small ions in the air. It now appears that the initially formed polonium ion is rapidly neutralized, but can become associated with other ions present. Reports by Jonassen (1984) and Jonassen and McLaughlin (1985) suggest that only 5 to 10% of the decay products are associated with highly mobile ions and that much of the activity is on large particles that have a bipolar charge distribution. 

Both polonium nuclides are alpha emitters and therefore of particular concern. In health physics it is customary to differentiate between attached and unattached 218Po the former, usually the larger of the two consists of 218Po atoms attached to airborne particles which are copiously present in virtually every atmosphere the latter consists of a 218Po atom or ion, frequently surrounded by several dozen molecules of a condensible species present in the air. The purpose of this paper is to present a new method for measuring the size properties of these unattached 218Po clusters. 

Similar affinity of polonium and plutonium for marine surfaces implies that studies of the more easily measured polonium might be valuable in predicting some consequences of plutonium disposal in die oceans [8-11]. Rates at which plutonium and polonium deposit out of seawater onto surfaces of giant brown algae and inert surfaces, such as glass and cellulose, suggest that both nuclides are associated in coastal seawater with colloidal sized species having diffusivities of about 3 x 10"7 cm2/s. The parallel behaviour possibly... 

In the environment, thorium and its compounds do not degrade or mineralize like many organic compounds, but instead speciate into different chemical compounds and form radioactive decay products. Analytical methods for the quantification of radioactive decay products, such as radium, radon, polonium and lead are available. However, the decay products of thorium are rarely analyzed in environmental samples. Since radon-220 (thoron, a decay product of thorium-232) is a gas, determination of thoron decay products in some environmental samples may be simpler, and their concentrations may be used as an indirect measure of the parent compound in the environment if a secular equilibrium is reached between thorium-232 and all its decay products. There are few analytical methods that will allow quantification of the speciation products formed as a result of environmental interactions of thorium (e.g., formation of complex). A knowledge of the environmental transformation processes of thorium and the compounds formed as a result is important in the understanding of their transport in environmental media. For example, in aquatic media, formation of soluble complexes will increase thorium mobility, whereas formation of insoluble species will enhance its incorporation into the sediment and limit its mobility. 

Hulubei s reported stable or long-lived isotope, if actually polonium, might be a nuclear isomer of a species which is already known. 

The group VIB cyanides, thiocyanates and selenocyanates and their complexes with species such as thiourea have been described.1,45 For example, the tellurium dithiocyanate complex has been prepared45 by treatment of tellurium dichloride or tellurium dibromide with ammonium thiocyanate. It seems that little information exists on the preparation of tellurocyanates and there is a sparsity of data on polonium derivatives. Indeed, the only known cyanide of polonium is probably a salt of the quadrivalent element.1... 

Studies of the solubility of polonium(IV) in formic, acetic, oxalic and tartaric acids have provided evidence of complex formation,48 with the acetato complex emerging as more stable than the hexachloro anion. Other studies of the solubility of polonium(IV) hydroxide in carbonate49 and nitrate50 solution, together with investigations51 of the ion exchange behaviour of polonium(IV) at high nitrate ion concentration, have been discussed in terms of the formation of anionic complex species. 

A number of other experiments carried out at tracer level concentrations are consistent with the formation of the hydroxide of Po and the polonite ion. Deposits of polonium on gold electrodes are solnble in boiling water and this has been attribnted to formation of Po(OH)4. Tracer level Po can be precipitated from its aqneons solntions in the presence of Bi(OH)3 or Fe(OH)3 carriers with alkali and is presumably carried as the hydroxide. Tracer level Po dissolves in aqneons alkah and the solnbihty increases with increasing concentration of hydroxide ion. Also, a nentral species, postulated to be Po(OH)4 was identified by paper chromatography. 

PDF 2. Chapter 29 Sulfur, Selenium, Tellurium and Polonium PDF 3. Chapter 30 Halogenium Species and Noble Gases... 

Already in the early days of radiochemistry some radionuclides were isolated from matrices and their mixtures were separated, making use of different volatility of various elements and compounds. Well-known is the role of the extreme volatility of radon in the discovery of emanations by Dorn and Rutherford (see a detailed story in Reference [1]). In her logbooks Mme. Curie noted purification of polonium by sublimation, when collecting deposits obtained at different temperatures [2], After the discovery of nuclear fission, the volatile species — Kr and Xe in the elemental state, As and Sb as gaseous ASH3 and SbH3, as well as Ru in the... 

It is interesting to note the compound HTel5-2oxin-10H2O, which has been reported to be isolated from a solution of oxine in hydroiodic acid containing teDurium. The instability constants for some tellurium halo complexes and the polonium iodo complexes including the POIf species, have been reported. 

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