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Germanium (Ge)

Germanium is the 32nd element, a metalloid in the p-block. Its standard atomic weight is 72.61.

Period 4Group 14p-blockMetalloid
32Ge

Germanium

72.61

What the table records

Atomic number
32
Standard atomic weight
72.61
Group
14
Period
4
Block
p-block
Category
Metalloid
Electron configuration
[Ar] 3d10 4s2 4p2
Valence electrons
4
Typical valence
4
Van der Waals radius
2.1 Å
Covalent radius
1.2 Å

The configuration above is the aufbau order.

Molecules containing germanium

How to read these numbers

The standard atomic weight is an average over the isotopes as they occur naturally, which is why it is rarely a whole number. It is the figure a molar mass calculation uses. Work in mass spectrometry wants the monoisotopic mass of a single isotope instead, which is a different number.

The two radii are not the same measurement. The covalent radius is half the distance between two bonded atoms of the element; the van der Waals radius is how close a non-bonded atom gets before repulsion takes over, and is always the larger. Space-filling models are drawn with the second, ball-and-stick models with the first — which is why the same molecule looks so different in the two.