WebElements

Periodic Table

germanium

Atomic number: 32
Atomic weight: 72.61
Symbol: Ge
Group number: 14
Electronic configuration: [Ar].3d10.4s2.4p2

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 (Rmax)
orbital s p d f
radius96.0119.826.9no 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.

ball-and-stick.gif

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
1st762.2
2nd1537.2
3rd3302
4th4410
5th9020

Isotopes

This section gives some data for naturally occurring isotopes.
Nominal mass Accurate mass % natural abundance
70Ge69.9242497 (16)21.23 (4)
72Ge71.9220789 (16)27.66 (3)
73Ge72.9234626 (16)7.73 (1)
74Ge73.9211774 (15)35.94 (2)
76Ge75.9214016 (17)7.44 (2)

Further Information

Copyright 1997 Mark Winter
Department of Chemistry at the University of Sheffield, Sheffield S3 7HF, England.

The current version of this document is at http://www.shef.ac.uk/~chem/web-elements-I/Ge.html