Amalgam

Amalgams are obtained by reacting a metal with mercury (when a metal surface is wetted with mercury) at normal temperatures or heated, electrolytically evolving a metal or cationic complex at a mercury cathode, or by other means. Many metals form stable compounds (mercury) with mercury.

Depending on the nature of the metal, its composition and temperature, amalgams can be homogeneous (liquid and solid solutions), solid intermetallic compounds or heterogeneous, in particular, gallium and mercury form two immiscible phases - a solution of gallium in mercury and a solution of mercury in gallium. Most metals with mercury form solid intermetallic compounds (mercurids), exceptions: zinc, aluminum, gallium, lead, bismuth, antimony.

The second component of amalgam in the alloy is in a fine dispersed state without an oxide film and therefore exhibits high chemical activity

When the amalgam is heated, the mercury is distilled off. Iron does not form amalgam, so mercury can be transported in steel vessels.

Amalgam is used in gilding metal products, in the production of mirrors , as well as in fluorescent lamps , including compact fluorescent lamps and induction lamps . Amalgams of alkali metals and zinc in chemistry are used as reducing agents . Amalgam is used in the electrolytic production of rare metals, the extraction of some metals from ores (see Amalgamation ). Amalgam is used for cold welding in microelectronics. In many countries, silver amalgam is still used in dentistry as a material for dental fillings.

In Unicode, there is an alchemical symbol of amalgam.

• Amalgam in dentistry

• Chemical Encyclopedia / Redkol .: Knunyants I.L. et al. - M .: Soviet Encyclopedia, 1988. - Vol. 1 (Abl-Dar). - 623 s.