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

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.

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.
Further Reading:  Functional Groups [with 21 MCQs]
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.

MCQs about Germanium Element

  • What is the atomic number of Germanium?
    • a) 30
    • b) 32
    • c) 40
    • d) 44
    • Answer: b) 32
  • Who named Germanium and why was it given that name?
    • a) Mendeleev, after a scientist
    • b) Winkler, after its place of discovery
    • c) Winkler, after its unique properties
    • d) Mendeleev, after the Latin word for silver
    • Answer: b) Winkler, after its place of discovery
  • When was Germanium discovered?
    • a) 1850
    • b) 1869
    • c) 1885
    • d) 1886
    • Answer: d) 1886
  • What is the primary source of Germanium?
    • a) Sphalerite
    • b) Quartz
    • c) Feldspar
    • d) Hematite
    • Answer: a) Sphalerite
  • What is the unique property of Germanium related to freezing?
    • a) It contracts like most materials
    • b) It expands like water
    • c) It becomes highly conductive
    • d) It becomes magnetic
    • Answer: b) It expands like water
  • Which of the following is a major use of Germanium?
    • a) Making steel
    • b) Producing fertilizers
    • c) Manufacturing camera lenses
    • d) Creating clothing
    • Answer: c) Manufacturing camera lenses
  • How is Germanium commonly doped to enhance its properties?
    • a) With silicon
    • b) With gallium and arsenic
    • c) With mercury
    • d) With aluminum
    • Answer: b) With gallium and arsenic
  • What is the primary use of Germanium in electronic devices?
    • a) Producing loudspeakers
    • b) Making batteries
    • c) Creating transistors and electronic circuits
    • d) Designing computer screens
    • Answer: c) Creating transistors and electronic circuits
  • In what field is Germanium used for its high refractive index and dispersion?
    • a) Agriculture
    • b) Medicine
    • c) Optics
    • d) Electronics
    • Answer: c) Optics
  • How many naturally occurring stable isotopes does Germanium have?
    • a) 3
    • b) 5
    • c) 7
    • d) 10
    • Answer: b) 5
  • What is the atomic mass of Germanium?
    • a) 22.45
    • b) 54.94
    • c) 72.63
    • d) 101.07
    • Answer: c) 72.63
  • Which element did Mendeleev predict before the discovery of Germanium?
    • a) Tin
    • b) Silicon
    • c) Lead
    • d) Aluminum
    • Answer: b) Silicon
  • What is the primary color of Germanium in its solid form?
    • a) Silver
    • b) Gold
    • c) Grey
    • d) Red
    • Answer: c) Grey
  • What is the role of Germanium in biological systems?
    • a) It is essential for human life
    • b) It is toxic
    • c) It has antibacterial properties
    • d) It is a major component of DNA
    • Answer: c) It has antibacterial properties
  • Which industry commonly uses Germanium as a catalyst?
    • a) Food industry
    • b) Automotive industry
    • c) Pharmaceutical industry
    • d) Textile industry
    • Answer: c) Pharmaceutical industry
  • What is the primary function of Germanium in infrared spectroscopes?
    • a) Enhancing color accuracy
    • b) Detecting ultraviolet light
    • c) Transmitting radio waves
    • d) Analyzing infrared radiation
    • Answer: d) Analyzing infrared radiation
  • What is the melting point of Germanium?
    • a) 1414°C
    • b) 938.25°C
    • c) 327.3°C
    • d) 573°C
    • Answer: b) 938.25°C
  • How is Germanium primarily obtained from the mining process?
    • a) As a primary element
    • b) As a by-product of sphalerite mining
    • c) Through artificial synthesis
    • d) From volcanic activities
    • Answer: b) As a by-product of sphalerite mining
  • What is the abundance percentage of the stable isotope 74Ge in Germanium?
    • a) 21.2%
    • b) 27.7%
    • c) 35.9%
    • d) 7.4%
    • Answer: c) 35.9%
Further Reading:  Iodine - History, Naming, Occurrence, Properties & Isotopes

Summary: Germanium Element Tutorial

In this comprehensive tutorial on Germanium, we explored various aspects of this semi-metal element. Here’s a summary of the key points covered:

  1. Introduction:
    • Germanium, with the symbol “Ge,” is a semi-metal located in group 14 of the periodic table.
    • It has an atomic number of 32, an atomic mass of 72.63, 32 electrons, 32 protons, and 42 neutrons.
  2. Naming and History:
    • The name “germanium” originates from the Latin word “Germania,” reflecting its discovery in Germany.
    • Predicted by Mendeleev in 1869, Clemens A. Winkler officially discovered germanium in 1886.
  3. Occurrence of Germanium:
    • Germanium is not abundantly found and is primarily present in minerals like argyrodite and germanite.
    • Major germanium production is through mining sphalerite, coal, and other ores.
  4. Properties of Germanium:
    • Germanium exhibits characteristics of a hard, lustrous, whitish-grey semi-metal.
    • It is a semiconductor with unique properties, including expansion on freezing like water.
    • The physical and chemical properties closely resemble silicon, being stable in air and water.
  5. Germanium in Biological Systems:
    • While germanium has no significant role in living organisms, studies suggest its effectiveness against bacteria.
    • Ongoing research explores potential pharmaceutical applications.
  6. Uses of Germanium:
    • Widely used in lens manufacturing for cameras and microscopes due to its high refractive index and dispersion.
    • Doped with gallium and arsenic, germanium enhances semiconductor properties for transistors and electronic circuits.
    • Applied in infrared spectroscopes, optical instruments, detectors, fluorescent lamps, and as a catalyst in various industries.
  7. Isotopes of Germanium:
    • Germanium has almost 30 known isotopes, with five naturally occurring stable isotopes.
    • Notable isotopes include 70Ge (21.2% abundance), 72Ge (27.7%), 73Ge (7.7%), 76Ge (7.4%), and 74Ge (35.9%).
Further Reading:  Rubidium: Occurrence, Properties, Uses, and Isotopes of Rubidium

This tutorial provides a comprehensive understanding of germanium, covering its discovery, properties, applications, and isotopic composition.