Germanium. Credit: Wikipedia.
Germanium (Ge) is a gray-white metalloid element of group IVA of the period table. Germanium takes the form of a brittle crystalline solid whose structure resembles that of diamond. It occurs naturally in sulfide ores of silver, copper, and zinc, and in certain coals, and is extracted as a by-product of processing them. It is important in transistors, rectifiers, and other similar semiconductor devices, and is also used in alloys and for lenses and windows for infrared radiation.
The chemical properties of germanium are intermediate between those of silicon and tin; it reacts with the halogens,
oxidizes in air at 600°C, and is attacked by concentrated oxidizing
acids and by fused alkalis. It forms covalent tetra- and divalent compounds
(see below). Its most common isotope is 74Ge (36.54%).
Germanium was predicted by the Russian chemist Dmitri Mendeleyev and discovered in 1886.
|relative atomic mass||72.59|
|melting point||937°C (1,719°F)|
|boiling point||2,830°C (5,126°F)|
Compounds of germanium
Germanium (IV) oxide (GeO2) is used in high-refractive-index glass. Melting point 1,086°C.
Germanium (IV) chloride (GeCl4) is a colorless liquid intermediate in the extraction of germanium and the preparation of most of its compounds. Melting point -50°C, boiling point 84°C.
The germanes are a series of volatile hydrides resembling the silanes.