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32Ge72.630
Metalloids (Semimetals)solid at STPP-block

Germanium

Group: 14Period: 4Standard Atomic Weight: 72.630 u

Why is Germanium in this position?

Understanding the scientific rationale behind Germanium's position in the periodic table:

Group Assignment
Group 14

Belongs to Group 14 because it has 4 valence electrons (4s² 4p²).

Period Assignment
Period 4

Belongs to Period 4 because its outermost electrons occupy n=4.

Orbital Block
P-block

Belongs to the p-block because its valence electrons occupy 4p orbitals.

Chemical Category
Metalloids (Semimetals)

Classified as a metalloid due to its semiconductor bandgap (0.66 eV) and diamond cubic crystal lattice.

Atomic Structure & Bohr Shell Model

Shell Distribution: [2, 8, 18, 4]

Bohr Atomic Shell Model(2, 8, 18, 4)

Hover or tap any shell orbit ring to inspect electron counts and 2n² capacities.

32 Protons (p⁺)41 Neutrons (n⁰)
KShell K: Electron 1 of 2Shell K: Electron 2 of 2LShell L: Electron 1 of 8Shell L: Electron 2 of 8Shell L: Electron 3 of 8Shell L: Electron 4 of 8Shell L: Electron 5 of 8Shell L: Electron 6 of 8Shell L: Electron 7 of 8Shell L: Electron 8 of 8MShell M: Electron 1 of 18Shell M: Electron 2 of 18Shell M: Electron 3 of 18Shell M: Electron 4 of 18Shell M: Electron 5 of 18Shell M: Electron 6 of 18Shell M: Electron 7 of 18Shell M: Electron 8 of 18Shell M: Electron 9 of 18Shell M: Electron 10 of 18Shell M: Electron 11 of 18Shell M: Electron 12 of 18Shell M: Electron 13 of 18Shell M: Electron 14 of 18Shell M: Electron 15 of 18Shell M: Electron 16 of 18Shell M: Electron 17 of 18Shell M: Electron 18 of 18NShell N: Electron 1 of 4Shell N: Electron 2 of 4Shell N: Electron 3 of 4Shell N: Electron 4 of 4GeZ = 32

Educational Note: This Niels Bohr planetary model visually illustrates principal quantum energy shells ($n=1, 2, 3\dots$) and electron counts. In modern quantum mechanics (Schrödinger model), electrons do not orbit in fixed circular planetary tracks, but exist as 3D probability clouds (orbitals: $s, p, d, f$) governed by the Heisenberg uncertainty principle.

Electron Shell Filling Breakdown

Shell K (n=1):2 / 2 electrons (100%)
Shell L (n=2):8 / 8 electrons (100%)
Shell M (n=3):18 / 18 electrons (100%)
Shell N (n=4):4 / 32 electrons (13%)
Aufbau Electron Configuration
1s² 2s² 2p⁶ 3s² 3p⁶ 3d¹⁰ 4s² 4p²

Neutral ground state configuration. Valence electrons: 4.

Atomic & Quantum Properties

Electronegativity (Pauling)2.01 Pauling
1st Ionization Energy762.2 kJ/mol
Electron Affinity-119 kJ/mol
Atomic Radius (empirical)125 pm
Common Oxidation States+4, +2
Crystal StructureDiamond Cubic

Physical & Thermal Properties

Density at STP5.32 g/cm³
Melting Point938.25 °C (1211.4 K)
Boiling Point2833 °C (3106 K)
Magnetic OrderingDiamagnetic
Discovery Year1886
Discovered ByClemens Winkler

Real-World Uses, Occurrence & Compounds

Major Industrial & Everyday Uses
  • Infrared night-vision optics and thermal imaging camera lenses
  • Fiber-optic telecommunications core glass dopant (GeO₂ increases refractive index)
  • High-speed silicon-germanium (SiGe) radio-frequency semiconductor chips
  • Polymerization catalysts for PET plastic bottle production
Occurrence in Nature

Extracted from sphalerite zinc ores, argyrodite, and certain coal fly ash deposits.

Etymology & Name Origin

From Latin 'Germania' meaning Germany

Important Chemical Compounds
GeO₂ (Germanium dioxide)
GeCl₄ (Germanium tetrachloride)
GeH₄ (Germane gas)
Interesting Chemical Facts
  • Germanium was predicted by Mendeleev in 1871 as 'eka-silicon'; Clemens Winkler verified every predicted physical and chemical property in 1886.
  • The first working transistor invented by Bardeen, Brattain, and Shockley in 1947 was made of germanium, not silicon.
  • Germanium is completely transparent to wideband infrared radiation, making it the premier material for thermal camera optics.
Safety & Handling Note

Elemental germanium is relatively non-toxic; germane gas (GeH₄) is extremely toxic and flammable.