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Chemical characterization of element 112

Authors :
Yu. Ts. Oganessian
A. I. Svirikhin
V. A. Gorshkov
N. V. Aksenov
V. I. Chepigin
Evgeny E. Tereshatov
A. V. Yeremin
Rugard Dressler
G. A. Bozhikov
Robert Eichler
S. V. Shishkin
Andreas Laube
O. N. Malyshev
V. Ya. Lebedev
A. V. Belozerov
M. Wegrzecki
O. V. Petrushkin
P. Rasmussen
A. V. Shutov
Heinz W. Gäggeler
S. N. Dmitriev
D. Piguet
Grigory K. Vostokin
F. Haenssler
M. G. Itkis
Source :
Nature. 447:72-75
Publication Year :
2007
Publisher :
Springer Science and Business Media LLC, 2007.

Abstract

Element 112 was discovered at the Heavy Ion Research Laboratory in Darmstadt, Germany in 1996. A decade on, and some of its chemical properties have now been determined. Irradiation of plutonium-242 with intense calcium-48 beams for three weeks produced two atoms of element 112 (not yet officially named, but commonly called ununbium), and that's enough to do some chemistry on if you are quick. Chemically ununbium behaves as a typical element of the group 12 in the periodic table (which it shares with Zn, Cd and Hg). It is very volatile and forms a metallic bond with a gold surface. An experiment has scrutinized two atoms of element 112, finding that it is very volatile and forms a metallic bond with a gold surface. These characteristics establish element 112 as a typical element of group 12. The heaviest elements to have been chemically characterized are seaborgium1 (element 106), bohrium2 (element 107) and hassium3 (element 108). All three behave according to their respective positions in groups 6, 7 and 8 of the periodic table, which arranges elements according to their outermost electrons and hence their chemical properties. However, the chemical characterization results are not trivial: relativistic effects on the electronic structure of the heaviest elements can strongly influence chemical properties4,5,6. The next heavy element targeted for chemical characterization is element 112; its closed-shell electronic structure with a filled outer s orbital suggests that it may be particularly susceptible to strong deviations from the chemical property trends expected within group 12. Indeed, first experiments concluded that element 112 does not behave like its lighter homologue mercury7,8,9. However, the production and identification methods10,11 used cast doubt on the validity of this result. Here we report a more reliable chemical characterization of element 112, involving the production of two atoms of 283112 through the alpha decay of the short-lived 287114 (which itself forms in the nuclear fusion reaction12 of 48Ca with 242Pu) and the adsorption of the two atoms on a gold surface. By directly comparing the adsorption characteristics of 283112 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. These adsorption characteristics establish element 112 as a typical element of group 12, and its successful production unambiguously establishes the approach to the island of stability of superheavy elements through 48Ca-induced nuclear fusion reactions with actinides.

Details

ISSN :
14764687 and 00280836
Volume :
447
Database :
OpenAIRE
Journal :
Nature
Accession number :
edsair.doi.dedup.....99ff35a0969e94c8d69dab63b120d520
Full Text :
https://doi.org/10.1038/nature05761