RhodiumRhodium is a lustrous, silver-white, chemically resistant metal, and is one of the platinum group metals in group VIII of the periodic table. It is the rarest of all non-radioactive metals. It has a face-centered cubic crystalline structure. It is insoluble in most acids, including aqua regia, but is dissolved in hot concentrated sulfuric acid.
Its primary use is as an alloying agent to harden platinum and palladium. Such alloys are used for furnace windings, thermocouple elements, bushings for glass fiber production, electrodes for aircraft spark plugs, and laboratory crucibles. It is useful as an electrical contact material as it has a low electrical resistance, a low and stable contact resistance, and is highly resistant to corrosion.
Rhodium's main contribution to improving lives is through its catalytic qualities, principally in catalytic converters. Rhodium has a higher melting point and lower density than platinum.
Its hardness makes it an excellent alloying agent to harden platinum. This hardness, along with its high melting point, high temperature stability and corrosion resistance, makes rhodium key to many industrial processes such as glass, glass fibre and nitric acid production.
Description: It is represented by the symbol of a rose, usually found with the motto "Dat Rosa Mel Apibus" ("The rose gives the bees honey") and was used by 17th century Rosicrucians.
Discovered By: William H. Wollaston
Discovered In: Britain, 1803
Origin: The name is derived from the Greek rhodon, meaning rose.
Chemical Symbol: Rh
Atomic Number: 45
Atomic Mass: 102.906