Ge
72.630Germanium
Germanyum
Germanium is a metalloid with atomic number 32. It is important in infrared optics, fiber-optic glass, semiconductor history, silicon-germanium electronics and Mendeleev’s eka-silicon prediction.
32
72.63 g/mol
[Ar] 3d¹⁰ 4s² 4p²
2 | 8 | 18 | 4
2.01
5.323 g/cm³
938.3 °C
2832.8 °C
Clemens Winkler
Germanium was discovered in 1886 by Clemens Winkler in the mineral argyrodite. Its properties closely matched Mendeleev’s predicted eka-silicon, another strong validation of the periodic table.
Germanium-70
Natural abundance: About 20.5%. Stable isotope of germanium.Germanium-72
Natural abundance: About 27.4%. Stable isotope of germanium.Germanium-73
Natural abundance: About 7.8%. Stable isotope used in NMR studies.Germanium-74
Natural abundance: About 36.5%. The most abundant stable isotope of germanium.Germanium-76
Natural abundance: About 7.8%. Long-lived isotope studied in double beta decay experiments.GeO₂
Germanium DioxideUsed in fiber-optic glass, infrared materials and as a catalyst-related precursor.GeCl₄
Germanium TetrachloridePrecursor for optical fiber production by vapor deposition.GeS₂
Germanium DisulfideChalcogenide glass material for infrared optics.SiGe
Silicon-Germanium AlloySemiconductor material used in high-frequency transistors and advanced electronics.- Infrared optics for thermal cameras and night-vision equipment
- Germanium dioxide in fiber-optic glass to adjust refractive index
- Silicon-germanium alloys in high-speed transistors and RF electronics
- Substrates for high-efficiency multi-junction solar cells
- Historical semiconductor material in early transistors
Germanium has no known essential biological role. Some organogermanium compounds have been marketed as supplements, but essentiality and broad health benefits are not scientifically established.
- The first transistor demonstrated at Bell Labs in 1947 used germanium.
- Germanium is opaque to visible light but transparent to much infrared radiation.
- Germanium dioxide can raise the refractive index of silica glass in optical fibers.
- Germanium was discovered after Mendeleev predicted eka-silicon with striking accuracy.
- Germanium has atomic number 32 and belongs to group 14.
- Its electron configuration is [Ar] 3d¹⁰ 4s² 4p².
- Germanium is a metalloid and semiconductor, like silicon.
- Common oxidation states are +4 and +2, with +4 more common in compounds such as GeO₂.
What is the atomic number of germanium?
The atomic number of germanium is 32.
What is the electron configuration of germanium?
Germanium has the electron configuration [Ar] 3d¹⁰ 4s² 4p².
What is germanium used for?
Germanium is used in infrared optics, fiber optics, silicon-germanium electronics, solar cells and semiconductor research.
Why is germanium important in transistor history?
The first practical transistor was made with germanium, helping launch modern electronics.
Why is germanium used in infrared optics?
Germanium transmits infrared radiation well while blocking visible light, making it useful for thermal imaging lenses.
What was eka-silicon?
Eka-silicon was Mendeleev’s predicted element that was later identified as germanium.