Helium basic properties

Noble gases are widely used in studies of the basic properties and dynamics of natural systems including the ocean. This chapter describes some of the more extensive applications of noble gases (mainly helium isotopes) to studies of oceanographic problems. They include the modem oceanic circulation, paleo-oceanography, hydro-thermal and cold brine systems in the deep ocean, and ocean/atmosphere gas exchange. 

Beaudry, B.J., and K.A. Gschneidner Jr, 1978, Preparation and basic properties of the rare earth metals, in Handbook on the Physics and Chemistry of Rare Earths, Vol. 1, eds K.A. Gschneidner Jr and L. Eyring (North-Holland, Amsterdam) eh. 2. Beavis, L.C., 1980, Metal Tritides Helium Emission, microfilm DAND79-0645 (Sandia National Laboratory, Albuquerque, NM). 

Following the development of quantum theory by Heisenberg [1] and Schrodinger [2] and a few further discoveries, the basic principles of the structure of atoms and molecules were described around 1930. Unfortunately, the complexity of the Schrodinger equation increases dramatically with the number of electrons involved in a system, and thus for a long time the hydrogen and helium atoms and simple molecules as H2 were the only species whose properties could really be calculated from these first principles. In 1929, Dirac [3] wrote ... 

All the elements form oxides except the three lightest noble gases, helium, neon, and argon, which form no stable compounds with any element. Oxides are often classified as acidic, basic, or amphoteric on the basis of their acid-base properties in aqueous solution. 

The weak van der Waals potential between He atoms and the bosonic nature of He also are basic for understanding why He is the only bulk superfluid below Tc = 2.18 if at 0.05 bar. The rare isotope He, a fermion, on the other hand, only becomes superfluid at a three orders of magnitude lower temperature. There are many well known macroscopic manifestations of superfluidity such as (i) flow without resistance (ii) a vanishing viscosity (iii) the ability to creep out of vessels against the forces of gravity (iv) the fountain effect which is driven by a type of Maxwell demon which separates the superfluid from the normal fluid components and (v) an enormous thermal conductivity which is 30 times greater than that of copper. Table 7.1 compares some properties of liquid argon (also a cry-omatrix) with those of helium in the normal and in the superfluid state. 

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