Germanium

General:

Name:Germanium Symbol:Ge
Type:Metalloid, Carbon group Atomic weight:72.59
Density @ 293 K:5.323 g/cm3 Atomic volume:13.6 cm3/mol
Discovered:

Germanium was discovered by Clemens A. Winkler in 1886. The element name comes from the Latin 'Germania', meaning Germany.

States

State (s, l, g):solid
Melting point:1210.6 K (938 °C) Boiling point:3103 K (2830 °C)

Energies

Specific heat capacity:0.32 J g-1 K-1 Heat of atomization:377 kJ mol-1
Heat of fusion:36.940 kJ mol-1 Heat of vaporization :334.3 kJ mol-1
1st ionization energy:762.1 kJ mol-1 2nd ionization energy:1537.4 kJ mol-1
3rd ionization energy:3301.7 kJ mol-1 Electron affinity:120 kJ mol-1

Oxidation & Electrons

Shells:2,8,18,4 Electron configuration:[Ar] 3d10 4s2 4p2
Minimum oxidation number: -4 Maximum oxidation number:4
Min. common oxidation no.: -4 Max. common oxidation no.:4
Electronegativity (Pauling Scale):2.01 Polarizability volume:6.1 Å3

Appearance & Characteristics

Structure:diamond structure Color:gray-white
Hardness:6 mohs
Harmful effects:

Germanium is not known to be toxic.

Characteristics:

Germanium is a lustrous, hard, gray-white semi-metallic element with a crystalline and brittle structure. Germanium also has the unusual property that (like water) it expands as it freezes. Four other elements expand when they freeze; silicon, bismuth, antimony and gallium. It is a semiconductor. Germanium and the oxide are transparent to infrared radiation.

Germanium also has the unusual property that (like water) it expands as it freezes. Four other elements expand when they freeze; silicon, bismuth, antimony and gallium.


Uses:

The most common use of germanium is as a semiconductor. Germanium is used in transistors and in integrated circuits. It is used as an alloying agent and as a catalyst. It is also used in infrared spectroscopes and infrared detectors. Some germanium compounds are useful because they are toxic to bacteria but are harmless for mammals.

Reactions

Reaction with air: mild, w/ht ⇒ GeO2 Reaction with 6 M HCl:none
Reaction with 15 M HNO3:mild,⇒ Geiv, Nox Reaction with 6 M NaOH:none

Compounds

Oxide(s):GeO, GeO2 Chloride(s):GeCl2, GeCl4
Hydride(s):GeH4, Ge2H6 + more

Radius

Atomic radius:122.3 pm Ionic radius (1+ ion): pm
Ionic radius (2+ ion):87 pm Ionic radius (3+ ion): pm
Ionic radius (2- ion): pm Ionic radius (1- ion): pm

Conductivity

Thermal conductivity:60.2 W m-1 K-1 Electrical conductivity:3 S cm-1

Abundance & Isotopes

Abundance earth's crust:1.5 parts per million by weight, 0.42 parts per million by moles
Abundance solar system:200 parts per billion by weight, 3 parts per billion by moles
Cost, pure:$360 per100g
Cost, bulk:$120 per 100g
Source:

The main ore of germanium is germanite, which is about 7% germanium. Commercially, germanium is obtained as a byproduct of metal refining and from some coal ashes.

Isotopes:

Germanium has 24 isotopes whose half-lives are known, with mass numbers 58 to 85. Of these, five are stable: 70Ge, 72Ge 73Ge, 74Ge and 76Ge. The most abundant is 74Ge at 35.9%.

Other

Other:

 

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