Science
Related: About this forumCopernecium forms a mercury like amalgam with gold.
I'm going through old papers I collected 10 years ago but never read, and I came across this oldie but goodie from 2007, which somehow found its way into a directory about the environmental and climate impact of large dams, along with an obituary of John Wheeler:
Chemical characterization of element 112 (R. Eichler, N. V. Aksenov, A. V. Belozerov, G. A. Bozhikov, V. I. Chepigin, S. N. Dmitriev, R. Dressler, H. W. Gäggeler, V. A. Gorshkov, F. Haenssler, M. G. Itkis, A. Laube, V. Ya. Lebedev, O. N. Malyshev, Yu. Ts. Oganessian, O. V. Petrushkin, D. Piguet, P. Rasmussen, S. V. Shishkin, A. V. Shutov, A. I. Svirikhin, E. E. Tereshatov, G. K. Vostokin, M. Wegrzecki & A. V. Yeremin, Nature volume 447, pages 7275 (03 May 2007))
One of the most dubious mining practices in the world is the extraction of gold from ores using liquid mercury, because mercury readily dissolves gold, which historically was the most problematic element to dissolve, at least until the discovery of a mixture of acids, hydrochloric and nitric acid, known as "aqua regia" because it dissolves "the king of metals." Aqua regia however is somewhat less effective when recovering gold from ores than mercury, and therefore mercury is still utilized for this purpose, particularly in wild cat mining of the type utilized to recover not only gold but many diffuse elements such as tantalum and the lanthanides, leading to distributed pollution that is difficult to address.
To recover gold from solution in liquid mercury, the mercury is distilled off.
Wonderful.
Anyway...
Element 112, now known as the element Copernicium, is a cogener of the toxic metals mercury and cadmium, the toxicity of which is largely an effect related to their displacing another cogener, zinc, in metalloenzymes, thus inactivating them.
The ten year old paper linked above refers to its chemistry, which has been the subject of some interest owing to relativistic corrections to its electronic structure, a topic to which the wonderful host of this group, directed my attention recently. It has not been clear whether or not Copernicium would be an inert gas rather like radon or a liquid. From the text:
The systematic order of the periodic table places element 112 in group 12, which also includes zinc, cadmium and mercury. It should thus have the closed-shell electronic ground state configuration Rn: 5f 146d107s 2, which implies noble metal characteristics16. However, relativistic calculations of atomic properties of superheavy elements suggest46 contraction of the spherical s- and p1/2-electron orbitals. The effect may increase the chemical stability of the elemental atomic state of element 112 beyond that of a noble metal and endow it with inertness more similar to that of the noble gas radon17, although recent relativistic calculations on element 112 predicted18 that it should form a semiconductor-like solid with clear chemical bonds. It was suggested19 that the questions of the bonding characteristics of element 112 and whether it more strongly resembles a noble metal or a noble gas might be addressed experimentally, by determining its gas adsorption properties on a noble metal surface such as gold. In fact, relativistic calculations indicate that the spin-orbit splitting of the 6d orbitals results in element 112 having a ground-state configuration with a 6d5/2 outermost valence orbital, which would make it behave like a noble transition metal20,21. Moreover, relativistic density functional calculations of its interaction with noble metals predict metallic interactions similar to those of the lighter homologue mercury2224...
... By directly comparing the adsorption characteristics of 283(Cn) to that of mercury and the noble gas radon, we find that element 112 is very volatile and, unlike radon, reveals a metallic interaction with the gold surface...
Some interesting details about this elegant experiment requiring significant teamwork:
Cool, I think.
The conclusion:
The added bold is mine.
(Cn substituted for 112 and Fl for 114 in the original text where needed to distinguish the mass number from the atomic number, owing to the inability to utilize superscripts here.)
The host here recently directed me to a wonderful paper on the effects of relativity on the chemistry of heavy elements, which by the way, is evoked to account for the fact that mercury is a liquid rather than a solid.
It is here: Relativistic Effects in Chemistry: More Common Than You Thought (Pyykkö, Annual Review of Physical Chemistry, Vol. 63:45-64 (Volume publication date May 2012)
Have a nice Daylight Savings Time Sunday afternoon.