Germanium Element: Occurrence, Properties, Uses, and Isotopes of Germanium


Germanium is a semi-metal present in group 14 of the periodic table. Its atomic number is 32 whereas its atomic mass is 72.63. Germanium has 32 electrons. It has 32 protons and 42 neutrons in its nucleus. Germanium is represented by the symbol “Ge”.

Naming and History

The germanium is from the Latin word “Germania” for Germany. It is because it was discovered in Germany.

  • Mendeleev

In 1869, Mendeleev predicted the element between silicon and tin in his periodic table. He named this unknown element Eka – silicon. According to him the atomic weight of the new element would be 70.

In September 1885, miners, mining at Freiberg came across new and unusual ore. This was given to Albin Weisbach. He sent it to a nearby mining academy which declared this unusual ore as a new unidentified element. Albin asked his colleague Winkler.

  • Clemens A. Winkler
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In 1886, Clemens A. Winkler discovered the element Germanium. He analyzed the sample of ore and concluded that it contained 17 – 18% sulphur, 73 – 75% silver, 0.2% mercury, and 6 – 7% of a new element which he named germanium.


Occurrence of Germanium

Germanium is not a much abundant element and is mostly present in minerals and ores. Argyrodite – a sulfide of silver and germanium, germanite containing 8% germanium. The major germanium is obtained as a by-product of the mining of sphalerite, coal, and other ores.

Properties of Germanium

Germanium is a hard, lustrous, whitish-grey semi-metal. It is brittle and crystalline. Germanium is a semiconductor and it also possesses the unique property of expansion on freezing like water. germanium is transparent to infrared radiations.

The physical and chemical properties of Germanium resemble more to silicon. It is stable in air and water. It does not react with acid and alkalis except nitric acid. The melting point of germanium is 938.25°C and its boiling point is 2833°C.

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It has a density of 5.323 grams per cubic centimeter. Germanium exists as a solid at room temperature.

Germanium in Biological Systems

There is no known significant role of germanium in livings. It is non-toxic. But some studies show its effectiveness against bacteria. Therefore, scientists are studying germanium on its use in pharmaceutics.

Uses of Germanium
  • The major use of germanium is in making wide camera lenses and lenses of microscopes. It is because it has a high refractive index and dispersion. Germanium oxide is used for this purpose.
  • Germanium is generally doped with gallium and arsenic to enhance its semiconductor properties. This doped germanium is used in making transistors, electronic circuits, etc.
  • Germanium is used in infrared spectroscopes, infrared optical instruments, and detectors.
  • Germanium is alloyed with other elements and used in fluorescent lamps.
  • Germanium is also used as a catalyst in various industries.
Isotopes of Germanium

Almost 30 isotopes of Germanium are known from mass ranging from Ge- 60 to Ge- 89. There are five naturally occurring stable isotopes of germanium. These are 70Ge with 21.2% abundance, 72Ge with 27.7%, 73Ge with 7.7%,76Ge with 7.4%, and 74Ge which is highly abundant with 35.9 percent.

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