Germanium

Germanium (Ge)

Lustrous hard metalloid element, belongs to group 14 of the periodic table. Forms a large number of organometallic compounds. Predicted by Mendeleev in 1871, it was actually found in 1886 by Winkler.
Atomic Number32
Atomic Weight72.63
Mass Number74
Group14
Period4
Blockp
Protons32 p+
Neutrons42 n0
Electrons32 e-
Germanium element.jpg Animated Bohr Model of Ge (Germanium) Enhanced Bohr Model of Ge (Germanium) Bohr Model: Ge (Germanium) Orbital Diagram of Ge (Germanium)

Properties

Atomic Radius
125 pm
Molar Volume
Covalent Radius
121 pm
Metallic Radius
124 pm
Ionic Radius
73 pm
Crystal Radius
87 pm
Van der Waals Radius
211 pm
Density
5.3234 g/cm³
Energy
Proton Affinity
Electron Affinity
1.232712 eV/particle
Ionization Energy
7.899435 eV/particle
Heat of Vaporization
328 kJ/mol
Heat of Fusion
36.8 kJ/mol
Heat of Formation
372 kJ/mol
Electrons
Electron Shells2, 8, 18, 4
Valence Electrons4
Electron Configuration[Ar] 3d10 4s2 4p2
Oxidation States-4, -3, -2, -1, 0, 1, 2, 3, 4
Electronegativity
2.01
Electrophilicity
1.5636638275958255 eV/particle
Phases
PhaseSolid
Gas Phase
Boiling Point
3,106.15 K
Melting Point
1,211.4 K
Critical Pressure
Critical Temperature
9,802.15 K
Triple Point
Visual
Color
Gray
Appearancegrayish-white
Refractive Index
Thermodynamic Properties
Thermal Conductivity
60.2 W/(m K)
Thermal Expansion
0.000006 1/K
Molar Heat Capacity
23.222 J/(mol K)
Specific Heat Capacity
Heat Capacity Ratio (Adiabatic Index)
Electrical Properties
TypeSemiconductor
Electrical Conductivity
0.002 MS/m
Electrical Resistivity
0.0005 m Ω
Superconducting Point
Magnetism
Typediamagnetic
Magnetic Susceptibility (Mass)
-0.0000000015 m³/Kg
Magnetic Susceptibility (Molar)
-0.000000000109 m³/mol
Magnetic Susceptibility (Volume)
-0.00000798
Magnetic Ordering
Curie Point
Neel Point
Structure
Crystal StructureFace Centered Cubic (DIA)
Lattice Constant
5.66 Å
Lattice Anglesπ/2, π/2, π/2
Mechanical Properties
Hardness
6 MPa
Bulk Modulus
Shear Modulus
Young Modulus
Poisson Ratio
Speed of Sound
5,400 m/s
Classification
CategoryMetalloids, Metalloids
CAS GroupIVB
IUPAC GroupIVA
Glawe Number84
Mendeleev Number89
Pettifor Number84
Geochemical Class
Goldschmidt Classchalcophile
Other
Gas Basicity
Dipole Polarizability
40 ± 1 a₀
C6 Dispersion Coefficient
354 a₀
Allotropes
Neutron Cross Section
2.2
Neutron Mass Absorption
0.0011
Quantum Numbers3P0
Space Group225 (Fm_3m)

Isotopes of Germanium

Stable Isotopes5
Unstable Isotopes28
Radioactive Isotopes28

58Ge

Abundance
Relative Atomic Mass
57.991863 ± 0.000537 Da
Mass Number58
G-Factor
0
Half Life
Spin0
Quadrupole Moment
0
Discovery Year
Parity+

58Ge Decay Modes
Decay ModeIntensity
2p (2-proton emission)%

59Ge

AbundanceRadioactive ☢️
Relative Atomic Mass
58.982426 ± 0.000429 Da
Mass Number59
G-Factor
Half Life
13.3 ± 1.7 ms
Spin7/2
Quadrupole Moment
Discovery Year2015
Parity-

59Ge Decay Modes
Decay ModeIntensity
β+ (β+ decay; β+ = ϵ + e+)100%
β+ p (β+-delayed proton emission)93%
2p (2-proton emission)0.2%

60Ge

AbundanceRadioactive ☢️
Relative Atomic Mass
59.970445 ± 0.000322 Da
Mass Number60
G-Factor
0
Half Life
21 ± 6 ms
Spin0
Quadrupole Moment
0
Discovery Year2005
Parity+

60Ge Decay Modes
Decay ModeIntensity
β+ (β+ decay; β+ = ϵ + e+)100%
β+ p (β+-delayed proton emission)100%
2p (2-proton emission)14%

61Ge

AbundanceRadioactive ☢️
Relative Atomic Mass
60.963725 ± 0.000322 Da
Mass Number61
G-Factor
Half Life
40.7 ± 0.4 ms
Spin3/2
Quadrupole Moment
Discovery Year1987
Parity-

61Ge Decay Modes
Decay ModeIntensity
β+ (β+ decay; β+ = ϵ + e+)100%
β+ p (β+-delayed proton emission)87%

62Ge

AbundanceRadioactive ☢️
Relative Atomic Mass
61.954761 ± 0.00015 Da
Mass Number62
G-Factor
0
Half Life
82.5 ± 1.4 ms
Spin0
Quadrupole Moment
0
Discovery Year1991
Parity+

62Ge Decay Modes
Decay ModeIntensity
β+ (β+ decay; β+ = ϵ + e+)100%
β+ p (β+-delayed proton emission)%

63Ge

AbundanceRadioactive ☢️
Relative Atomic Mass
62.949628 ± 0.00004 Da
Mass Number63
G-Factor
Half Life
153.6 ± 1.1 ms
Spin3/2
Quadrupole Moment
Discovery Year1991
Parity-

63Ge Decay Modes
Decay ModeIntensity
β+ (β+ decay; β+ = ϵ + e+)100%
β+ p (β+-delayed proton emission)%

64Ge

AbundanceRadioactive ☢️
Relative Atomic Mass
63.941689912 ± 0.000004 Da
Mass Number64
G-Factor
0
Half Life
63.7 ± 2.5 s
Spin0
Quadrupole Moment
0
Discovery Year1972
Parity+

64Ge Decay Modes
Decay ModeIntensity
β+ (β+ decay; β+ = ϵ + e+)100%

65Ge

AbundanceRadioactive ☢️
Relative Atomic Mass
64.939368136 ± 0.000002323 Da
Mass Number65
G-Factor
Half Life
30.9 ± 0.5 s
Spin3/2
Quadrupole Moment
Discovery Year1972
Parity-

65Ge Decay Modes
Decay ModeIntensity
β+ (β+ decay; β+ = ϵ + e+)100%
β+ p (β+-delayed proton emission)0.011%

66Ge

AbundanceRadioactive ☢️
Relative Atomic Mass
65.933862124 ± 0.000002577 Da
Mass Number66
G-Factor
0
Half Life
2.26 ± 0.05 h
Spin0
Quadrupole Moment
0
Discovery Year1950
Parity+

66Ge Decay Modes
Decay ModeIntensity
β+ (β+ decay; β+ = ϵ + e+)100%

67Ge

AbundanceRadioactive ☢️
Relative Atomic Mass
66.932716999 ± 0.000004636 Da
Mass Number67
G-Factor
Half Life
18.9 ± 0.3 m
Spin1/2
Quadrupole Moment
0
Discovery Year1950
Parity-

67Ge Decay Modes
Decay ModeIntensity
β+ (β+ decay; β+ = ϵ + e+)100%

68Ge

AbundanceRadioactive ☢️
Relative Atomic Mass
67.928095305 ± 0.000002014 Da
Mass Number68
G-Factor
0
Half Life
271.05 ± 0.08 d
Spin0
Quadrupole Moment
0
Discovery Year1948
Parity+

68Ge Decay Modes
Decay ModeIntensity
ϵ (electron capture)100%

69Ge

AbundanceRadioactive ☢️
Relative Atomic Mass
68.927964467 ± 0.000001414 Da
Mass Number69
G-Factor
0.294 ± 0.0028
Half Life
39.05 ± 0.1 h
Spin5/2
Quadrupole Moment
0.114 ± 0.007
Discovery Year1938
Parity-

69Ge Decay Modes
Decay ModeIntensity
β+ (β+ decay; β+ = ϵ + e+)100%

70Ge

Abundance
20.52 ± 0.19
Relative Atomic Mass
69.924248542 ± 0.00000088 Da
Mass Number70
G-Factor
0
Half Life
Spin0
Quadrupole Moment
0
Discovery Year1923
Parity+

71Ge

AbundanceRadioactive ☢️
Relative Atomic Mass
70.92495212 ± 0.000000874 Da
Mass Number71
G-Factor
Half Life
11.43 ± 0.03 d
Spin1/2
Quadrupole Moment
0
Discovery Year1941
Parity-

71Ge Decay Modes
Decay ModeIntensity
ϵ (electron capture)100%

72Ge

Abundance
27.45 ± 0.15
Relative Atomic Mass
71.922075824 ± 0.000000081 Da
Mass Number72
G-Factor
0
Half Life
Spin0
Quadrupole Moment
0
Discovery Year1923
Parity+

73Ge

Abundance
7.76 ± 0.08
Relative Atomic Mass
72.923458954 ± 0.000000061 Da
Mass Number73
G-Factor
-0.19516444444444 ± 0.000011111111111111
Half Life
Spin9/2
Quadrupole Moment
-0.196 ± 0.001
Discovery Year1933
Parity+

74Ge

Abundance
36.52 ± 0.12
Relative Atomic Mass
73.92117776 ± 0.000000013 Da
Mass Number74
G-Factor
0
Half Life
Spin0
Quadrupole Moment
0
Discovery Year1923
Parity+

75Ge

AbundanceRadioactive ☢️
Relative Atomic Mass
74.92285837 ± 0.000000055 Da
Mass Number75
G-Factor
1.018 ± 0.01
Half Life
82.78 ± 0.04 m
Spin1/2
Quadrupole Moment
0
Discovery Year1939
Parity-

75Ge Decay Modes
Decay ModeIntensity
β (β decay)100%

76Ge

AbundanceRadioactive ☢️
7.75 ± 0.12
Relative Atomic Mass
75.921402725 ± 0.000000019 Da
Mass Number76
G-Factor
0
Half Life
1.88 ± 0.08 Zy
Spin0
Quadrupole Moment
0
Discovery Year1933
Parity+

76Ge Decay Modes
Decay ModeIntensity
(double β decay)100%

77Ge

AbundanceRadioactive ☢️
Relative Atomic Mass
76.923549843 ± 0.000000056 Da
Mass Number77
G-Factor
Half Life
11.211 ± 0.003 h
Spin7/2
Quadrupole Moment
Discovery Year1939
Parity+

77Ge Decay Modes
Decay ModeIntensity
β (β decay)100%

78Ge

AbundanceRadioactive ☢️
Relative Atomic Mass
77.922852911 ± 0.000003795 Da
Mass Number78
G-Factor
0
Half Life
88 ± 1 m
Spin0
Quadrupole Moment
0
Discovery Year1953
Parity+

78Ge Decay Modes
Decay ModeIntensity
β (β decay)100%

79Ge

AbundanceRadioactive ☢️
Relative Atomic Mass
78.925359506 ± 0.000039893 Da
Mass Number79
G-Factor
Half Life
18.98 ± 0.03 s
Spin1/2
Quadrupole Moment
0
Discovery Year1970
Parity

79Ge Decay Modes
Decay ModeIntensity
β (β decay)100%

80Ge

AbundanceRadioactive ☢️
Relative Atomic Mass
79.925350773 ± 0.000002205 Da
Mass Number80
G-Factor
0
Half Life
29.5 ± 0.4 s
Spin0
Quadrupole Moment
0
Discovery Year1972
Parity+

80Ge Decay Modes
Decay ModeIntensity
β (β decay)100%

81Ge

AbundanceRadioactive ☢️
Relative Atomic Mass
80.928832941 ± 0.000002205 Da
Mass Number81
G-Factor
Half Life
9 ± 2 s
Spin9/2
Quadrupole Moment
Discovery Year1972
Parity+

81Ge Decay Modes
Decay ModeIntensity
β (β decay)100%

82Ge

AbundanceRadioactive ☢️
Relative Atomic Mass
81.929774031 ± 0.000002405 Da
Mass Number82
G-Factor
0
Half Life
4.31 ± 0.19 s
Spin0
Quadrupole Moment
0
Discovery Year1972
Parity+

82Ge Decay Modes
Decay ModeIntensity
β (β decay)100%

83Ge

AbundanceRadioactive ☢️
Relative Atomic Mass
82.9345391 ± 0.000002604 Da
Mass Number83
G-Factor
Half Life
1.85 ± 0.06 s
Spin5/2
Quadrupole Moment
Discovery Year1972
Parity+

83Ge Decay Modes
Decay ModeIntensity
β (β decay)100%
β n (β-delayed neutron emission)%

84Ge

AbundanceRadioactive ☢️
Relative Atomic Mass
83.93757509 ± 0.000003403 Da
Mass Number84
G-Factor
0
Half Life
951 ± 9 ms
Spin0
Quadrupole Moment
0
Discovery Year1972
Parity+

84Ge Decay Modes
Decay ModeIntensity
β (β decay)100%
β n (β-delayed neutron emission)10.6%

85Ge

AbundanceRadioactive ☢️
Relative Atomic Mass
84.942969658 ± 0.000004003 Da
Mass Number85
G-Factor
Half Life
495 ± 5 ms
Spin3/2
Quadrupole Moment
Discovery Year1991
Parity+

85Ge Decay Modes
Decay ModeIntensity
β (β decay)100%
β n (β-delayed neutron emission)17.2%
2n (2-neutron emission)%

86Ge

AbundanceRadioactive ☢️
Relative Atomic Mass
85.946967 ± 0.00047 Da
Mass Number86
G-Factor
0
Half Life
221.6 ± 11 ms
Spin0
Quadrupole Moment
0
Discovery Year1994
Parity+

86Ge Decay Modes
Decay ModeIntensity
β (β decay)100%
β n (β-delayed neutron emission)45%

87Ge

AbundanceRadioactive ☢️
Relative Atomic Mass
86.953204 ± 0.000322 Da
Mass Number87
G-Factor
Half Life
103 ± 4 ms
Spin5/2
Quadrupole Moment
Discovery Year1997
Parity+

87Ge Decay Modes
Decay ModeIntensity
β (β decay)100%
β n (β-delayed neutron emission)%
2n (2-neutron emission)%

88Ge

AbundanceRadioactive ☢️
Relative Atomic Mass
87.957574 ± 0.000429 Da
Mass Number88
G-Factor
0
Half Life
61 ± 6 ms
Spin0
Quadrupole Moment
0
Discovery Year1997
Parity+

88Ge Decay Modes
Decay ModeIntensity
β (β decay)100%
β n (β-delayed neutron emission)%
2n (2-neutron emission)%

89Ge

AbundanceRadioactive ☢️
Relative Atomic Mass
88.96453 ± 0.000429 Da
Mass Number89
G-Factor
Half Life
Spin3/2
Quadrupole Moment
Discovery Year1997
Parity+

89Ge Decay Modes
Decay ModeIntensity
β (β decay)%
β n (β-delayed neutron emission)%
2n (2-neutron emission)%

90Ge

AbundanceRadioactive ☢️
Relative Atomic Mass
89.969436 ± 0.000537 Da
Mass Number90
G-Factor
0
Half Life
Spin0
Quadrupole Moment
0
Discovery Year2010
Parity+

90Ge Decay Modes
Decay ModeIntensity
β (β decay)%
β n (β-delayed neutron emission)%
2n (2-neutron emission)%

History

In 1869, Dmitri Mendeleev predicted its existence and some of its properties based on its position on his periodic table and called the element eka-silicon. In 1886, Clemens Winkler found the new element along with silver and sulfur, in a rare mineral called argyrodite. The first silicon-germanium alloys were obtained in 1955. From the Latin word Germania, Germany

DiscoverersClemens Winkler
Discovery LocationGermany
Discovery Year1886
Etymology (Name Origin)Latin: Germania (Germany).
Pronunciationjer-MAY-ni-em (English)
Germanium is not known to be toxic
Germanium and the oxide are transparent to infrared radiation

Uses

The most common use of germanium is as a semiconductor in electronics. 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. Widely used in semiconductors. It is a good semiconductor when combined with tiny amounts of phosphorus, arsenic, gallium, and antimony.

Sources

Obtained from refining copper, zinc and lead.

Abundance
Abundance in Earth's crust
1.5 mg/kg
Abundance in Oceans
0.00005 mg/L
Abundance in Human Body
Abundance in Meteor
0.0021 %
Abundance in Sun
0.00002 %
Abundance in Universe
0.00002 %

Nuclear Screening Constants

1s0.7063
2p3.9178
2s8.6352
3d15.7487
3p14.9864
3s14.2103
4p25.2196
4s23.9564