Difficulty: Easy
Correct Answer: 4
Explanation:
Introduction / Context:
Semiconductor bonding and band structure originate from the valence electron configuration. Silicon, the workhorse of microelectronics, forms covalent bonds using its outer-shell electrons.
Given Data / Assumptions:
Concept / Approach:
Valence electrons are those in the outermost shell participating in bonding. For Si, the outer shell is n = 3 with 3s² 3p², totaling 4 valence electrons. This tetra-valence enables sp³ covalent bonding in the diamond cubic crystal structure.
Step-by-Step Solution:
Identify outer shell: n = 3.Count electrons in 3s and 3p: 2 + 2 = 4.Hence, valence electrons = 4.
Verification / Alternative check:
Group IV (14) elements in the periodic table (C, Si, Ge, Sn) all have 4 valence electrons, consistent with tetrahedral bonding.
Why Other Options Are Wrong:
2, 1, or 0 contradict the electron configuration; 6 would suit Group 16 elements, not Group 14.
Common Pitfalls:
Confusing total electrons with valence electrons; overlooking shell structure.
Final Answer:
4
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