Assign germanium's oxidation state in GeH4 (germane) and GeO2.
In GeH4, H is +1, so Ge = -4 — the metalloid can go negative with hydrogen, mirroring methane. In GeO2, O is -2, so Ge = +4. Partner electronegativity decides the sign.
What Is the Charge of Germanium?
Germanium commonly forms Ge2+ Ge4+ in introductory ionic compounds.
Germanium's principal state is +4, as in GeO2 and GeCl4 — the compounds used to make fiber-optic glass. The +2 state (GeO, GeCl2) exists but is a reducing agent, eager to climb back to +4.
| Element | Germanium |
|---|---|
| Symbol | Ge |
| Atomic number | 32 |
| Common ionic charge | +2, +4 |
| Common ions | Ge2+, Ge4+ |
Visual reference
Germanium element image and atomic model
Images are used as visual references; charge rules still depend on the compound.
What Germanium's electrons actually do
Germanium is [Ar]3d10 4s2 4p2, carbon's group two rows down. All four outer electrons engage for the +4 state. Down this group the s-pair grows lazier about bonding (the 'inert pair effect'), so +2 begins appearing at germanium — a preview of tin, where the two states genuinely compete.
Where intuition fails with Germanium
Expecting germanium to form ionic salts like a metal. It is a metalloid: GeCl4 is a volatile liquid, not a crystal lattice of Ge4+ ions. Use +4 for bookkeeping and formula prediction, not as a literal ion.
Worked example: Ge in a formula problem
Ge2+ and Ge4+ in real compounds
GeCl2
Germanium chloride
Ge2+ balances chloride ions.
GeO
Germanium oxide
Germanium can form oxides where total positive and negative charge balances.
Questions students ask about germanium
What was germanium's role in early electronics?
The first transistor (1947) was germanium at charge 0 — a neutral semiconductor crystal. Silicon later displaced it for handling heat better, but Ge still appears in high-speed chips and infrared optics.
Is 'organic germanium' in supplements a Ge ion?
Marketed supplements contain germanium-carbon compounds (Ge formally +4). Regulators have flagged them for kidney toxicity — no biological need for germanium exists, at any charge.
Why does germanium sit on the metal-nonmetal dividing line?
Its middling electronegativity (2.01) and four valence electrons mean it neither gives electrons away like tin nor hoards them like carbon. The staircase on the periodic table runs right through its box.
How do I use this charge in formulas?
Combine positive and negative ions so the total charge is zero — or let the ionic compound calculator do the crossing for you. The full chart lives on the periodic table with charges.
Where this data comes from
Charges and element facts on this page are checked against the primary references below. Found an error? Email hello@periodictablewithcharges.com — corrections ship in the next content update. See how this site is edited.