• Class: Metals
• Period: 4
• IUPAC group: 14
• Traditional: IVb

• Discovered in: 1886 by Winkler
• Origin of name: Latin: Germania, (Germany)
• Historical or alternate name:

Argyrodite, germanite, Zinc ores, coal & in other minerals

Silvery white, brittle metaloid. Unaffected by alkalis and most (except nitric) acids. STABLE in air and water.

• Atmosphere: ~0.0 ppm
• Primitive mantle: 1.2 ppm
• Sea water: 1e-4 ppm
• Metallic meteorite: 32.2 ppm
• Continental crust: 1.6 ppm
• Solar photosphere: 3.50 log of abundance
• Oceanic crust: 1.5 ppm
• Solar system: 118.0 relative to Si=1.0e6

   Hazards

Can ignite or react violently with oxidants. Compounds low toxicity..

• Lower:0.01
• Upper:1.0

Germanium Physical Properties

 Transitional Data

• State: Solid
• Density: 5.35 g/cm3

 Molar enthalpy

• Atomization: 373.80 kJ mol-1
• Fusion: 34.7 kJ mol-1
• Vaporization: 327.6 kJ mol-1

 Transition points

• Melting point: 1210.6 K
• Boiling point: 3103.0 K
• Critical temperature: 8400.0 K

 Molar properties

• Atomic weight: 72.61 g/mole
• Molar volume: 13.716 cm3 mol-1

 Crystal structure sequence

diamond-cubic

 Thermodynamics

• State: solid
  • Enthalpy 0
  • Gibbs function 0
  • Entropy 31.09
  • Heat Capacity 23.347

• State: gas
  • Enthalpy 376.6
  • Gibbs function 335.9
  • Entropy 157.900
  • Heat Capacity 30.731

 Miscellaneous physical

• Electrical resistivity: 4.6 E7 µ-ohms/cm
• Debye temperature: 374.0 K
• Thermal conductivity: 59.9 W / m / K
• Coefficient of linear expansion: 5.8Coef. per K
• Mass magnetic susceptibility: -1.328e-9
• X-ray diffraction mass absorption coefficients:
• CuK: 75.6 (µ/p)/cm2 g-1
• MoK: 64.8 (µ/p)/cm2 g-1

Germanium Chemical Properties

 Chemical basics:

• Oxidation states: +2 +4
• Molecular wt: 72.61 g/mole

 Radii

• Covalent: 122 pm
• Atomic: 139.0 pm
• Van der Waals: pm

 Ions:

• ion: +2 pm 73.0
• ion: +4 pm 53.0

 Covalent bonds

 Effective nuclear charge

• Slater: 5.65
• Clementi: 6.78
• Froese-Fischer: 7.92

 Electronegativity

• Pauling: 1.8
• Allred-Rochow: 2.02

 Standard reactions

Germanium Nuclear Properties

• Known 17
• Listed 8

• Known 65 - 78
• Listed 68 - 76

• % Occ.:Natural
• Mossbauer NRA:
• Nuclear spin/Quantum no.:
• Radioisotopes:
  • Half-life: 288.0 days
  • Decay mode: E.C.,
  • Source:
• Notes med

• % Occ.:Natural 20.5%
• Mossbauer NRA:
• Nuclear spin/Quantum no.:
• Radioisotopes:
  • Half-life:
  • Decay mode:
  • Source:
• Notes

• % Occ.:Natural
• Mossbauer NRA:
• Nuclear spin/Quantum no.:
• Radioisotopes:
  • Half-life: 11.2 days
  • Decay mode: E.C.,
  • Source:
• Notes

• % Occ.:Natural 27.4%
• Mossbauer NRA:
• Nuclear spin/Quantum no.:
• Radioisotopes:
  • Half-life:
  • Decay mode:
  • Source:
• Notes

• % Occ.:Natural 7.8%
• Mossbauer NRA: 2.131
• Nuclear spin/Quantum no.: 9/2
• Radioisotopes:
  • Half-life:
  • Decay mode:
  • Source:
• Notes

• % Occ.:Natural
• Mossbauer NRA: 10.730 *
• Nuclear spin/Quantum no.:
• Radioisotopes:
  • Half-life:
  • Decay mode:
  • Source:
• Notes

• % Occ.:Natural 36.5%
• Mossbauer NRA:
• Nuclear spin/Quantum no.:
• Radioisotopes:
  • Half-life:
  • Decay mode:
  • Source:
• Notes

• % Occ.:Natural 7.8%
• Mossbauer NRA:
• Nuclear spin/Quantum no.:
• Radioisotopes:
  • Half-life:
  • Decay mode:
  • Source:
• Notes

• Isotope Cross-section 2.3±0.3 barns

• Absolute sensitivity: 1.08e-4 1H=1.0
• Relative sensitivity: 1.4e-3 1H=1.0
• Receptivity: 0.617 13C=1.0
• Magnetogyric ratio: -0.9331e7 rad / T / s
• Quadropole moment: -0.2e-28 m2
• Frequency: 3.488 MHz
• Reference: Ge(CH3)4

Germanium Energy Properties

Electrons

• Ground state electron configuration: [Ar] 3d10 4s2 4p2
• Electron affinity: 116 kJ mol-1
• Filling orbitals:

Spectral lines

 Ionization energies

 Atomic energy levels