Ge
Germanium
Element 32 · Metalloid
Germanium (Ge)
Germanium is a shiny, brittle metalloid. It was used in the first transistors and is now vital to fibre optics and infrared optics.
- Metalloid
- Period 4
- Group 14
- p-block
- solid at room temperature
Key properties
- Atomic mass
- 72.63
- u
- Electron configuration
- [Ar] 3d10 4s2 4p2
- Melting point
- 938.3 °C
- 1,211.4 K
- Boiling point
- 2,832.9 °C
- 3,106 K
- Density
- 5.323 g/cm³
- Electronegativity
- 2.01
- Pauling
- Atomic radius
- 211 pm
- van der Waals
- 1st ionisation energy
- 7.9 eV
Compare with every element:Electronegativity chartAtomic radius chartIonisation energy chartDensity chart of the elementsMelting point chartElectron configuration chart
Did you know?
Notable facts about germanium
- 01
Mendeleev predicted germanium as “eka-silicon” 15 years before it was found.
- 02
The first transistor, built at Bell Labs in 1947, used germanium.
- 03
Germanium is transparent to infrared light, so thermal cameras use germanium lenses.
Applications
What is germanium used for?
- Fibre-optic cables
- Infrared optics and night vision
- Solar cells for satellites
- Polymerisation catalysts
History
Discovery & name origin
Atomic structure
Atomic properties
Atomic structure
Atomic properties
- Atomic number
- 32
- Atomic mass
- 72.63 u
- Group
- 14
- Period
- 4
- Block
- p-block
- Electron configuration
- [Ar] 3d10 4s2 4p2
- Full configuration
- 1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p2
- Electrons per shell
- 2, 8, 18, 4
- Electronegativity (Pauling)
- 2.01
- Electron affinity
- 1.35 eV
- Atomic radius (van der Waals)
- 211 pm
- Stable isotopes
- 4
Oxidation states
Highlighted: common oxidation states (+4, +2).
Successive ionisation energies
Energy to remove each electron in turn (kJ/mol). Big jumps show where a new, inner shell begins.
- 1st762
- 2nd1,537.5
- 3rd3,302.1
- 4th4,411
- 5th9,020
Physical
Physical properties & colour
Physical
Physical properties & colour
- State at 20 °C
- Solid
- Melting point
- 1,211.4 K · 938.3 °C · 1,720.9 °F
- Boiling point
- 3,106 K · 2,832.9 °C · 5,131.1 °F
- Density
- 5.323 g/cm³
- Molar heat capacity
- 23.222 J/(mol·K)
- Appearance
- Greyish-white
- CPK model colour
- Copied
The CPK colour is the convention used for this element’s atoms in molecular models.
FAQ
Germanium questions
What is Ge on the periodic table?
Ge is the symbol for germanium, element 32 on the periodic table. It sits in group 14, period 4, in the metalloid category, and has an atomic mass of 72.63.
What is the atomic number of germanium?
Germanium has atomic number 32, so every germanium atom has 32 protons in its nucleus. Its symbol is Ge and its atomic mass is 72.63.
Who discovered germanium?
Germanium was discovered by Clemens Winkler in 1886 (Germany). The name comes from Latin Germania, “Germany”.
What is germanium used for?
Germanium is used for: fibre-optic cables; infrared optics and night vision; solar cells for satellites; polymerisation catalysts.
Is germanium a metal?
No. Germanium is classed as a metalloid, with properties between metals and nonmetals.
What is the electron configuration of germanium?
The electron configuration of germanium is [Ar] 3d10 4s2 4p2. Its 32 electrons are arranged in shells as 2, 8, 18, 4.