Chemical properties of Gemanium
- Atomic number:
- 32
- Atomic mass:
- 72.63 g.mol -1
- Electronegativity according to:
- 1.96
- Density:
- 5.323 g.cm-3 at 20°C
- Melting point:
- 928 °C
- Boiling point:
- 2833 °C
- Vanderwaals radius:
- 0.211 nm
- Ionic radius:
- 0.122 nm (+5) ; 0,120 nm (+3)
- Isotopes:
- 5
- Electronic shell:
- [ Kr ] 4d10 5S2 5p2
- Energy of first ionisation:
- 762 kJ.mol -1
Germanium is a chemical element with symbol Ge and atomic number 32. It is a lustrous, hard, grayish-white metalloid in thecarbon group, chemically similar to its group neighbors tin and silicon. Purified germanium is a semiconductor, with an appearance most similar to elemental silicon. Like silicon, germanium naturally reacts and forms complexes with oxygen in nature. Unlike silicon, it is too reactive to be found naturally on Earth in the free (native) state.
Applications
The major end uses for germanium in 2007, worldwide, were estimated to be: 35% for fiber-optic systems, 30% infrared optics, 15% forpolymerization catalysts, and 15% for electronics and solar electric applications.[24] The remaining 5% went into other uses such as phosphors, metallurgy, and chemotherapy. The most notable physical characteristics of germania (GeO2) are its high index of refraction and its low optical dispersion. Silicon-germanium alloys are rapidly becoming an important semiconductor material, for use in high-speed integrated circuits.
Gemanium in the environment
About 118 tonnes of germanium was produced in 2011 worldwide, mostly in China (80 t), Russia (5 t) and United States (3 t). Germanium is recovered as a by-product from sphalerite zinc ores where it is concentrated in amounts of up to 0.3%,especially from low-temperature sediment-hosted, massive Zn–Pb–Cu(–Ba) deposits and carbonate-hosted Zn–Pb deposits. A recent study found that at least 10,000 t of extractable germanium is contained in known zinc reserves, particularly those hosted by Mississippi-Valley type deposits, while at least 112,000 t is contained in coal reserves. In 2007 35% of the demand was met by recycled germanium.
Applications
The major end uses for germanium in 2007, worldwide, were estimated to be: 35% for fiber-optic systems, 30% infrared optics, 15% forpolymerization catalysts, and 15% for electronics and solar electric applications.[24] The remaining 5% went into other uses such as phosphors, metallurgy, and chemotherapy. The most notable physical characteristics of germania (GeO2) are its high index of refraction and its low optical dispersion. Silicon-germanium alloys are rapidly becoming an important semiconductor material, for use in high-speed integrated circuits.
Gemanium in the environment
About 118 tonnes of germanium was produced in 2011 worldwide, mostly in China (80 t), Russia (5 t) and United States (3 t). Germanium is recovered as a by-product from sphalerite zinc ores where it is concentrated in amounts of up to 0.3%,especially from low-temperature sediment-hosted, massive Zn–Pb–Cu(–Ba) deposits and carbonate-hosted Zn–Pb deposits. A recent study found that at least 10,000 t of extractable germanium is contained in known zinc reserves, particularly those hosted by Mississippi-Valley type deposits, while at least 112,000 t is contained in coal reserves. In 2007 35% of the demand was met by recycled germanium.
