Germanium (Ge) as a group-IV element How many valence electrons does a germanium atom have in its outer shell?

Introduction / Context:
Germanium (Ge) is a classic semiconductor used in diodes and transistors. Its position in the periodic table determines its bonding behavior and electronic properties through the number of valence electrons.

Given Data / Assumptions:

• Germanium atomic number Z = 32.
• Electron configuration: [Ar] 3d^10 4s^2 4p^2.
• Valence shell is the n = 4 shell (4s and 4p).

Concept / Approach:
Valence electrons are those in the outermost s and p orbitals that participate in bonding. For Ge, 4s^2 and 4p^2 provide a total of 4 valence electrons, enabling tetrahedral covalent bonding in the diamond lattice similar to silicon and carbon (diamond).

Step-by-Step Solution:
Write Ge configuration: [Ar] 3d^10 4s^2 4p^2.Count outer-shell electrons: 2 (4s) + 2 (4p) = 4.Conclude germanium has 4 valence electrons.

Verification / Alternative check:
Group-IV (14) elements—C, Si, Ge, Sn, Pb—share the valence of 4, consistent with tetrahedral sp^3 bonding in semiconductors.

Why Other Options Are Wrong:
2, 1, or 0 valence electrons would place Ge in alkaline earth, alkali, or noble gas groups, which it is not. 8 would imply a filled outer shell (noble gas), inconsistent with Ge chemistry.

Common Pitfalls:
Counting 3d electrons as valence; for main-group chemistry in solids, the d^10 set is core-like and not counted as valence.

Final Answer:
4