The "profile" of neon becomes more exact

07-29-2010: Small or large, quiet or communicative - the fundamental characteristics of a person form his/her behaviour. In principle, it is the same with chemical elements. And the better the "profile" of an element is known, the better its behaviour can be understood and controlled in practical applications as, for example, in the chemical industry. In the past years, such "profiles" have been developed with an ever increasing frequency on the basis of theoretical models. Whether they really provide a good reproduction of reality can now be checked with the aid of a method which can only be found in metrological world-class research: in Germany at PTB, where a fundamental characteristic of the noble gas neon - i.e. its polarizability - has been determined with more precision than ever with the aid of dielectricity constant gas thermometry. The value determined shows that the last practical measurements of this quantity, which were performed 40 years ago, have - obviously - not been so good, whereas latest theoretical models fit very well. The PTB physicists' results met with great interest on the part of fundamental chemists, because the procedure does not only serve in this special case, but also allows the respective models to be checked for other fundamental characteristics and other elements. In addition, the experimental determination of the polarizability of neon has great practical importance for the determination of a fundamental constant, i.e. the Boltzmann constant which is of primary importance for thermodynamics.