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Germanium [Ge] 

 
CAS-ID: 7440-56-4
An: 32 N: 41
Am: 72.64 g/mol
Group No: 14
Group Name: Metalloids
Block: p-block  Period: 4
State: solid at 298 K
Colour: greyish white Classification: Semi-metallic
Boiling Point: 3093K (2820°C)
Melting Point: 1211.4K (938.3°C)
Density: 5.323g/cm3
 
Discovery Information
Who: Clemens Winkler
When: 1886
Where: Germany
 
Name Origin
Latin: Germania (Germany).
 "Germanium" in different languages.
 
Sources
Obtained from refining copper, zinc and lead. It can be found in argyrodite (Ag8GeS6), coal, germanite (Cu13Fe2Ge2S16), zinc ores as well as other minerals. About 80 tons are produced each year.
 
Abundance
 Universe: 0.2 ppm (by weight)
 Sun: 0.2 ppm (by weight)
 Carbonaceous meteorite: 21 ppm
 Earth's Crust: 1.8 ppm
 Seawater:
   Atlantic surface: 7 x 10-8 ppm
   Atlantic deep: 1.4 x 10-7 ppm
   Pacific surface: 3.5 x 10-7 ppm
   Pacific deep: 6 x 10-6 ppm
 
Uses
Widely used in semiconductors, infrared prisms (for night vision goggles), reflectors in projectors, wide angle lenses and dentistry.
Germanium transistors are still used in some effects pedals by musicians who wish to reproduce the distinctive tonal character of the "fuzz"-tone from the early rock and roll era. Vintage effects pedals known to contain germanium transistors have shown marked increases in collector value for this reason alone.
 
History
In 1871, germanium (Latin Germania for Germany) was one of the elements that Dmitri Mendeleev predicted to exist as a missing analogue of the silicon group (Mendeleev called it "ekasilicon"). The existence of this element was proven by Clemens Winkler in 1886. This discovery was an important confirmation of Mendeleev's idea of element periodicity.
The development of the germanium transistor opened the door to countless applications of solid state electronics. From 1950 through the early 1970s, this area provided an increasing market for germanium, but then high purity silicon began replacing germanium in transistors, diodes, and rectifiers. Silicon has superior electrical properties, but requires much higher purity samples-a purity which could not be commercially achieved in the early days. Meanwhile, demand for germanium in fiber optics communication networks, infrared night vision systems, and polymerization catalysts increased dramatically. These end uses represented 85% of worldwide germanium consumption for 2000.
 
Notes
Its occurrence is 0.0007% of the earth's crust. In the elemental form it is a lustrous white, brittle metalloid. When crystalized it has a diamond cubic structure. It is a poor conductor and is used in electronics in rectifying devices and transistors. It is also used in dental alloys. There are several compounds which contain germanium. "Germaine" or germanium hydride is a colourless gas GeH4 prepared by the action of lithium aluminium hydride on germanium halide in an ether solution. Germaine is a hazardous substance UN2192 which is classified as a poisonous gas (2.3). It is also a flammable gas (2.1). Other compounds include : Germanium dichloride GeCl2, Germanium dioxide GeO2, Germanium tetrachloride GeCl4 this is very irritating to eyes and membranes.
 
Hazards
Certain compounds of germanium have low toxicity to mammals, but have toxic effects against certain bacteria. This property makes these compounds useful as chemotherapeutic agents.

All about Germanium

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