ABSTRACT
Elemental mercury is the only metal that is liquid at room temperature (melting temperature TM = −38.83°C); the only other low melting metal is gallium (TM = 29.76°C) [1]. is has been known since ancient times and is re ected in the Greek name Hydrargyrum meaning “watery silver” and the Latin Argentum vivum meaning “quick silver.” It is speculated that its low melting point is due to relativistic e ects [2-4], which energetically lowers the 6s band substantially [5], thus making mercury a very hard atom with a static dipole polarizability of only αD = 5.025(50) Å3 [6,7]. It is clear that such strong and pronounced relativistic e ects for the 6s shell [5], which are close to the relativistic 6s maximum of gold [4,8], makes mercury rather unique in chemical and physical properties among the other Group 12 metals zinc and cadmium. Some of the physical and chemical properties of the Group 12 elements are compared in Table 3.1, and in many of these properties we see anomalies that, most likely, are caused by relativistic e ects. For the next Group 12 element (below Hg) with nuclear charge Z = 112 (Copernicium, Cn), even larger relativistic e ects are predicted [9-11], and the dipole polarizability of this element is now the lowest of all the Group 12 elements (αD(112) = 3.8 Å3) [12].
