Germanium

Germanium, 32Ge
Grayish lustrous block with uneven cleaved surface
Germanium
Pronunciation/ɜːrˈmniəm/ (jur-MAY-nee-əm)
Appearancegrayish-white
Standard atomic weight Ar°(Ge)
Germanium in the periodic table
Hydrogen Helium
Lithium Beryllium Boron Carbon Nitrogen Oxygen Fluorine Neon
Sodium Magnesium Aluminium Silicon Phosphorus Sulfur Chlorine Argon
Potassium Calcium Scandium Titanium Vanadium Chromium Manganese Iron Cobalt Nickel Copper Zinc Gallium Germanium Arsenic Selenium Bromine Krypton
Rubidium Strontium Yttrium Zirconium Niobium Molybdenum Technetium Ruthenium Rhodium Palladium Silver Cadmium Indium Tin Antimony Tellurium Iodine Xenon
Caesium Barium Lanthanum Cerium Praseodymium Neodymium Promethium Samarium Europium Gadolinium Terbium Dysprosium Holmium Erbium Thulium Ytterbium Lutetium Hafnium Tantalum Tungsten Rhenium Osmium Iridium Platinum Gold Mercury (element) Thallium Lead Bismuth Polonium Astatine Radon
Francium Radium Actinium Thorium Protactinium Uranium Neptunium Plutonium Americium Curium Berkelium Californium Einsteinium Fermium Mendelevium Nobelium Lawrencium Rutherfordium Dubnium Seaborgium Bohrium Hassium Meitnerium Darmstadtium Roentgenium Copernicium Nihonium Flerovium Moscovium Livermorium Tennessine Oganesson
Si

Ge

Sn
galliumgermaniumarsenic
Atomic number (Z)32
Groupgroup 14 (carbon group)
Periodperiod 4
Block  p-block
Electron configuration[Ar] 3d10 4s2 4p2
Electrons per shell2, 8, 18, 4
Physical properties
Phase at STPsolid
Melting point1211.40 K ​(938.25 °C, ​1720.85 °F)
Boiling point3106 K ​(2833 °C, ​5131 °F)
Density (at 20° C)5.327 g/cm3[3]
when liquid (at m.p.)5.60 g/cm3
Heat of fusion36.94 kJ/mol
Heat of vaporization334 kJ/mol
Molar heat capacity23.222 J/(mol·K)
Vapor pressure
P (Pa) 1 10 100 1 k 10 k 100 k
at T (K) 1644 1814 2023 2287 2633 3104
Atomic properties
Oxidation states−4, −3, −2, −1, 0,[4] +1, +2, +3, +4 (an amphoteric oxide)
ElectronegativityPauling scale: 2.01
Ionization energies
  • 1st: 762 kJ/mol
  • 2nd: 1537.5 kJ/mol
  • 3rd: 3302.1 kJ/mol
Atomic radiusempirical: 122 pm
Covalent radius122 pm
Van der Waals radius211 pm
Color lines in a spectral range
Spectral lines of germanium
Other properties
Natural occurrenceprimordial
Crystal structureface-centered diamond-cubic (cF8)
Lattice constant
Diamond cubic crystal structure for germanium
a = 565.774 pm (at 20 °C)[3]
Thermal expansion5.79×10−6/K (at 20 °C)[3]
Thermal conductivity60.2 W/(m⋅K)
Electrical resistivity1 Ω⋅m (at 20 °C)
Band gap0.67 eV (at 300 K)
Magnetic orderingdiamagnetic[5]
Molar magnetic susceptibility−76.84×10−6 cm3/mol[6]
Young's modulus103 GPa[7]
Shear modulus41 GPa[7]
Bulk modulus75 GPa[7]
Speed of sound thin rod5400 m/s (at 20 °C)
Poisson ratio0.26[7]
Mohs hardness6.0
CAS Number7440-56-4
History
Namingafter Germany, homeland of the discoverer
PredictionDmitri Mendeleev (1869)
DiscoveryClemens Winkler (1886)
Isotopes of germanium
Main isotopes[8] Decay
abun­dance half-life (t1/2) mode pro­duct
68Ge synth 270.8 d ε 68Ga
70Ge 20.5% stable
71Ge synth 11.3 d ε 71Ga
72Ge 27.4% stable
73Ge 7.76% stable
74Ge 36.5% stable
76Ge 7.75% 1.78×1021 y ββ 76Se
 Category: Germanium
| references

Germanium is a chemical element; it has symbol Ge and atomic number 32. It is lustrous, hard-brittle, grayish-white and similar in appearance to silicon. It is a metalloid in the carbon group that is chemically similar to its group neighbors silicon and tin. Like silicon, germanium naturally reacts and forms complexes with oxygen in nature.

Because it seldom appears in high concentration, germanium was found comparatively late in the discovery of the elements. Germanium ranks 55th in relative abundance of the elements in the Earth's crust. In 1869, Dmitri Mendeleev predicted its existence and some of its properties from its position on his periodic table, and called the element ekasilicon. On February 6, 1886, Clemens Winkler at Freiberg University found the new element, along with silver and sulfur, in the mineral argyrodite. Winkler named the element after his country of birth, Germany. Germanium is mined primarily from sphalerite (the primary ore of zinc), though germanium is also recovered commercially from silver, lead, and copper ores.

Elemental germanium is used as a semiconductor in transistors and various other electronic devices. Historically, the first decade of semiconductor electronics was based entirely on germanium. Presently, the major end uses are fibre-optic systems, infrared optics, solar cell applications, and light-emitting diodes (LEDs). Germanium compounds are also used for polymerization catalysts and have most recently found use in the production of nanowires. This element forms a large number of organogermanium compounds, such as tetraethylgermanium, useful in organometallic chemistry. Germanium is considered a technology-critical element.[9]

Germanium is not thought to be an essential element for any living organism. Similar to silicon and aluminium, naturally-occurring germanium compounds tend to be insoluble in water and thus have little oral toxicity. However, synthetic soluble germanium salts are nephrotoxic, and synthetic chemically reactive germanium compounds with halogens and hydrogen are irritants and toxins.

  1. ^ "Standard Atomic Weights: Germanium". CIAAW. 2009.
  2. ^ Prohaska, Thomas; Irrgeher, Johanna; Benefield, Jacqueline; Böhlke, John K.; Chesson, Lesley A.; Coplen, Tyler B.; Ding, Tiping; Dunn, Philip J. H.; Gröning, Manfred; Holden, Norman E.; Meijer, Harro A. J. (2022-05-04). "Standard atomic weights of the elements 2021 (IUPAC Technical Report)". Pure and Applied Chemistry. doi:10.1515/pac-2019-0603. ISSN 1365-3075.
  3. ^ a b c Arblaster, John W. (2018). Selected Values of the Crystallographic Properties of Elements. Materials Park, Ohio: ASM International. ISBN 978-1-62708-155-9.
  4. ^ "New Type of Zero-Valent Tin Compound". Chemistry Europe. 27 August 2016.
  5. ^ Magnetic susceptibility of the elements and inorganic compounds, in Handbook of Chemistry and Physics 81st edition, CRC press.
  6. ^ Weast, Robert (1984). CRC, Handbook of Chemistry and Physics. Boca Raton, Florida: Chemical Rubber Company Publishing. pp. E110. ISBN 0-8493-0464-4.
  7. ^ a b c d "Properties of Germanium". Ioffe Institute.
  8. ^ Kondev, F. G.; Wang, M.; Huang, W. J.; Naimi, S.; Audi, G. (2021). "The NUBASE2020 evaluation of nuclear properties" (PDF). Chinese Physics C. 45 (3): 030001. doi:10.1088/1674-1137/abddae.
  9. ^ Avarmaa, Katri; Klemettinen, Lassi; O’Brien, Hugh; Taskinen, Pekka; Jokilaakso, Ari (June 2019). "Critical Metals Ga, Ge and In: Experimental Evidence for Smelter Recovery Improvements". Minerals. 9 (6): 367. Bibcode:2019Mine....9..367A. doi:10.3390/min9060367.

From Wikipedia, the free encyclopedia · View on Wikipedia

Developed by Nelliwinne