ABSTRACT
The element mercury is aptly named after the messenger of the Roman gods, as it is the most mobile of all the metals. In its ground or zero-oxidation state (Hg0), mercury is the only metal that is liquid at room temperature. Liquid metallic mercury can form stable amalgams with a number of other metals. An amalgam with silver and copper is the basis of dental amalgam tooth fillings. Both the amalgam and liquid phases allow mercury to vaporize as a monatomic gas (usually referred to as mercury vapor). Mercury has two oxidation states each capable of forming a variety of chemical compounds. In the mercurous state, two atoms of mercury, each having lost one electron, form the mercurous ion (Hg-Hg++). Mercuric mercury (Hg++), where two electrons have been lost from one atom of the metal, forms most of the compounds of mercury.
