germanium

• Description
• General information
• Physical data
• Radii
• Electronegativities
• Solid state structure
• Temperatures
• Enthalpies
• Ionization Enthalpies
• Isotopes
• Further information

Description

The element is a gray-white metalloid, and in its pure state is crystalline and brittle, retaining its lustre in air at room temperature. It is a very important semiconductor material. Zone-refining techniques have led to production of crystalline germanium for semiconductor use with an impurity of only one part in 10^-10.

Certain germanium compounds have a low mammalian toxicity, but a clear activity against certain bacteria, which makes them of interest as chemotherapeutic agents.

General information

Discoveror: Clemens Winkler
Date discovered: 1886
Discovered at: Germany
Meaning of name: From the Latin word "Germania" meaning "Germany"

Physical data

Standard state: solid at 298 K
Colour: greyish white
Density of solid at ambient temperature/kg m^-3: 5323
Molar volume/cm³: 13.63

Radii /pm

Atomic: 125
Covalent (single bond):
Pauling radius for the ion [Ge]^-: 371

Valence shell orbital radius maxima (R_max)

orbital	s	p	d	f
radius	96.0	119.8	26.9	no data

Electronegativities

Both values are quoted on the Pauling scale.

Pauling: 2.01
Allred Rochow: 2.02

Crystal Structure

structure: ccp (cubic close-packed)

The following CrystalMaker image represents the solid state structure. For most elements, the most stable allotrope is illustrated. Try WebElements version 2 for interactive virtual reality and CHIME images.

Temperatures (/K)

melting point: 1211.4
boiling point: 3093

Enthalpies /kJ mol^-1

fusion: 36.8
vaporization: 334

single bond enthalpies:

Ge-F	Ge-Cl	Ge-Br	Ge-I	Ge-Ge
452	349	276	212	263.5

Ionization enthalpies /kJ mol^-1

Number	Enthalpy
1st	762.2
2nd	1537.2
3rd	3302
4th	4410
5th	9020

Isotopes

This section gives some data for naturally occurring isotopes.

Nominal mass	Accurate mass	% natural abundance
70Ge	69.9242497 (16)	21.23 (4)
72Ge	71.9220789 (16)	27.66 (3)
73Ge	72.9234626 (16)	7.73 (1)
74Ge	73.9211774 (15)	35.94 (2)
76Ge	75.9214016 (17)	7.44 (2)

Further Information

• Additional information about WebElements 1.2.2
• This is a licensed copy (here is the full list) of WebElements 1.2.2 and contains a subset of the material contained within the main version of WebElements (version 2)
• For further information please try WebElements version 2
• Sheffield Chemdex: perhaps the largest internet chemistry directory
• Sheffield Chemputer: interactive chemistry calculators on the WWW