Germanium (Ge)

Germanium properties

Atomic number

32

Atomic mass

72.63 u

Category

Metalloid

Group

14

Period

4

Block

p-block

State at room temp.

Solid

Electronegativity

2.01

Melting point

1,211.4 K (938.3 °C)

Boiling point

3,106 K (2,832.8 °C)

Density

5.323 g/cm³

Valence electrons

4

Common charges

+4, −4

Oxidation states

+4, +2

Atomic radius

211 pm

Ionization energy

7.9 eV

Electron affinity

1.35 eV

Radioactive

No, has stable isotopes

Discovered

1886

Germanium electron configuration

The electron configuration of Germanium (Ge) is [Ar] 3d10 4s2 4p2. Its 32 electrons are arranged in shells as 2, 8, 18, 4.

Protons, neutrons and electrons in Germanium

A neutral Germanium atom has 32 protons and 32 electrons. Most Germanium atoms have about 41 neutrons: the atomic mass rounded to 73, minus the atomic number 32.

Neutrons are approximate: atoms of the same element can have different numbers of neutrons (isotopes). Atomic number and mass

How many valence electrons does Germanium have?

4

Germanium has 4 valence electrons in its outermost shell, shell 4. These are the electrons involved in chemical bonding.

See every element: Periodic table with valence electrons

Germanium orbital diagram

Each box is an orbital that holds up to two electrons with opposite spins (↑↓). The inner shells are the same as the noble gas in brackets. How to write electron configurations

Molar mass of Germanium

72.63 g/mol

One mole of Germanium atoms (6.022 × 10²³ atoms) has a mass of 72.63 grams. Use this value to convert between grams and moles.

Germanium facts

• Germanium's atomic mass and density closely matched the values Dmitri Mendeleev had predicted in 1871 for an undiscovered element he called 'eka-silicon'.
• The first transistor, built at Bell Labs in 1947, was made using a crystal of germanium.
• Germanium (Ge) has atomic number 32 and is a solid at room temperature. It was discovered in 1886.

Position in the periodic table

Germanium is element 32, in period 4 and group 14 of the periodic table, in the p-block.

All metalloids

Uses of Germanium

Germanium is transparent to infrared light, so it is used for lenses and windows in thermal imaging cameras and night-vision equipment. Germanium dioxide is added to the glass core of optical fibers to guide light signals, and it serves as a catalyst for making some PET plastic. Germanium is also used in high-efficiency solar cells for spacecraft and in fast silicon-germanium chips.

Who discovered Germanium?

German chemist Clemens Winkler discovered germanium in 1886 in Freiberg, Saxony, while analyzing a newly found silver mineral called argyrodite. He named it after his home country, Germany.

Where does the name come from?

Germanium comes from Germania, the Latin name for Germany. Clemens Winkler, who discovered the element in 1886, named it in honor of his home country.

Discovery timeline