Chemical elements

Bohrium Properties


Properties of chemical elements can be derived from the position in the periodic table of elements, which corresponds to the configuration of the electronic structure of atoms. For the heaviest chemical elements, the deviations in the periodic law are expected due to acceleration of electrons from a high improbability density orbitals near nucleus to relativistic velocities with subsequent increasing of binding energies, orbital contractions and more effective screening of the nuclear charge and destabilization of the outer d and f orbitals. Then, for the heaviest chemical elements we should expect an unusual chemical properties, which can be differ from those required by periodic law.

Bohrium-267 is most suitable isotope due to the long half-time period (T1/2 = 17seconds). 267Bh was synthesized in the following nuclear fusion reaction:

249Bk + 22Ne -> 267Bh + 4n

Bohrium atoms synthesized in this reaction were adsorbed onto the surface of carbon particles suspended in helium gas with further heating to 1000°C with HCl and O2 gases with further submitting of this mixture to the detector system at 180°C. Analysis of the adsorption of BhO3Cl on quartz yields the standard adsorption enthalpy to be -75 kJ/mol. Adsorption enthalpy of BhO3Cl is stronger than adsorption enthalpy for TcO3Cl (-51 kJ/mol) and ReO3Cl (-61 kJ/mol). On the basis of empirical correlations it is possible to estimate the standard sublimation enthalpy of BhO3Cl as 89+21-18 kJ/mol in compare with 49+12-12 kJ/mol and 66+12-12 kJ/mol for TcO3Cl and ReO3Cl, respectively. On the basis of this experiment it is possible to conclude that Bohrium forms a volatile oxychloride compound with the properties typical for the group 7 of the periodic table. The volatility of Bohrium oxychloride compound is less than those for Rhenium and Technetium which is within a good agreement with relativistic calculations of molecular properties and with the classical extrapolations of the periodic law for this group of the periodic table.

© Copyright 2008-2012 by