Germanium

Properties
Atomic symbol |  Ge
Atomic number |  32
Classification |  Group IVA, Carbon family
Atomic mass |  72.59
Number of Stable Isotopes |  70, 72, 73, 74, 76
Number of Unstable Isotopes |  66, 67, 68, 69, 71, 75, 77, 78
Melting point (°C) |  937.4 (1,720.85 °F)
Boiling point (°C) |  2,830 (5,131 °F)
Density (grams per cc) |  5.323
Hardness (Moh's scale) |  6.25
Abundance in lithosphere (%) |  0.0007
Oxidation states |  +2, +4
Other Information
Date of discovery |  1886
Name of discoverer |  Clemens Winkler
Name origin |  From the Latin word Germania, Germany
Uses |  Semiconductors
Obtained from |  Refining of copper, zinc, lead

Germanium (jer-MAY-ni-em) is a brittle, silvery-white semi-metal (metalloid).[1]

## Contents

* 1 History
* 2 Uses
* 3 References
* 4 External links

## History[edit]

Germanium was first proposed to exist by Dmitri Mendeleyev in 1871. He had recently created a Periodic Table of Elements, and identified gaps which where unknown elements. Germanium was officially discovered in 1886 by Clemens Winkler, a German chemist. He found it in the mineral argyrodite (Ag8GeS6).

Periodic Table of the Elements

1  | 2  | 3  | 4  | 5  | 6  | 7  | 8  | 9  | 10  | 11  | 12  | 13  | 14  | 15  | 16  | 17  | 18

1.008

|  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |

4.003

6.939

9.0122

|  |  |  |  |  |  |  |  |  |  |

10.811

12.011

14.007

15.999

18.998

10.183

22.99

24.312

|  |  |  |  |  |  |  |  |  |  |

26.982

28.086

30.974

32.064

35.453

39.948

39.102

40.08

44.956

47.9

50.942

51.996

54.938

55.847

58.933

58.71

63.546

65.37

69.72

72.59

74.922

78.96

79.904

83.8

85.47

87.62

88.905

91.22

92.906

95.94

[97]

101.07

102.91

106.4

107.87

112.4

114.82

118.69

121.75

127.6

126.9

131.3

132.91

137.34

57*

138.91

178.49

180.95

183.85

186.2

190.2

192.2

195.09

196.97

200.59

204.37

207.19

208.98

210

210

222

215

226.03

89**

227.03

104

[261]

105

[262]

106

[266]

107

[264]

108

[265]

109

[268]

110

[271]

111

[272]

112

[277]

113

[284]

114

[289]

115

[288]

116

[292]

117

[293]

118

[294]

|  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
*Lanthanides  |

140.12

140.91

144.24

145

150.35

151.96

157.25

158.92

162.5

164.93

167.26

168.93

173.04

174.97

|  |
|  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
**Actinides  |

232.04

231

238.03

237.05

239.05

241.06

244.06

249.08

252.08

252.08

100

257.1

101

258.1

102

259.1

103

262.11

|  |
|  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |

## Uses[edit]

Germanium is primarily used as a semiconductor. With arsenic, gallium, indium, antimony or phosphorus, it is used to make transistors. Another major use for Germanium is lenses. It is used in the manufacture of wide-angle camera lenses and objective lenses for microscopes.[2] It is also used to create alloys and as a phosphor in fluorescent lamps.[3] Additionally, adding 1% germanium to silver prevents tarnishing.[4]

## References[edit]

1. ↑ http://www.rsc.org/periodic-table/element/32/germanium
2. ↑ http://www.rsc.org/periodic-table/element/32/germanium
3. ↑ http://education.jlab.org/itselemental/ele032.html
4. ↑ http://www.rsc.org/periodic-table/element/32/germanium

## External links[edit]

* http://chemistry.about.com/od/elementfacts/a/germanium.htm