Page 181 - Academic Press Encyclopedia of Physical Science and Technology 3rd InOrganic Chemistry

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Encyclopedia of Physical Science and Technology EN008H-970 June 29, 2001 16:46

Liquid Alkali Metals

C. C. Addison
University of Nottingham

I. Some Modern Applications
II. Basic Physical and Chemical Properties
III. Manipulation of the Liquids
IV. Purification
V. Alkali Metal Mixtures
VI. Species Formed by Dissolved Elements
VII. Electrical Resistivity
VIII. Reactions between Dissolved Elements
IX. Corrosion by the Liquid Alkali Metals

GLOSSARY of the liquid medium, with consequent release of
energy.
Coolant Fluid used to carry away heat from the core of a
reactor.
Eutectic Term applied to the particular mixture of THE ALKALI METALS lithium, sodium, potassium,
two or more substances that has the lowest melting rubidium, and cesium constitute the first group of ele-
point. ments in the periodic table and have quite exceptional
Fast nuclear reactor Reactor in which the neutrons are properties. They have low melting points and can be ma-
not slowed down by moderators. nipulated readily in the liquid state. The liquids are find-
Getter Element (usually a solid metal) that reacts with, ing ever-increasing use as coolant fluids in, for example,
and thereby removes, dissolved impurities in liquid fast nuclear reactors and high-temperature storage batter-
metals by forming insoluble products. ies. The liquids also have low viscosity, low density and
Ionization potential Energy required to detach an high thermal conductivity, which makes them particularly
electron from an isolated gaseous atom of the suited for use as heat-transfer media. The liquid alkali
element. metals can also act as solvents for other elements such
Solute Constituent of a solution that is considered to be as carbon, oxygen, nitrogen, hydrogen, and heavier ele-
dissolved in a liquid, termed the solvent. ments. The presence of these elements in solution renders
Solvation Process whereby an atom or ion dissolved the liquid metals corrosive, but techniques have now been
in a liquid attracts to itself atoms or molecules developed for their monitoring and removal.

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