Band gaps of elements — match each element (List I) with an approximate energy band gap value at room temperature (List II). List I (Element) A. C (diamond form) B. Si C. Ge D. Sn E. Pb List II (Approx. band gap Eg) 1. 7 eV 2. 1.15 eV 3. 0.75 eV 4. 0.1 eV 5. 0 eV (metal)

Introduction / Context:
Band gap values classify materials as insulators, semiconductors, or metals. Knowing typical Eg helps predict conductivity, optical properties, and device applications.

Given Data / Assumptions:

• Values are approximate room-temperature band gaps for the elemental forms listed.
• Diamond (C) is a wide-bandgap insulator; Si and Ge are classic semiconductors; Sn and Pb behave as semimetal/metal with very small or zero gaps.

Concept / Approach:

Map each element to a representative Eg: diamond has a very large gap; Si is about 1.1 eV; Ge is below 1 eV; gray tin can be near-semimetal with very small Eg; metals like Pb have Eg ≈ 0.

Step-by-Step Solution:

Verification / Alternative check:

Reference semiconductor tables place Si at ~1.12 eV and Ge at ~0.66 eV; diamond is often quoted 5.5–7 eV depending on definition; metals have overlapping bands yielding Eg ≈ 0.

Why Other Options Are Wrong:

• Swapping Si and Ge contradicts well-known semiconductor parameters.
• Assigning nonzero Eg to Pb contradicts metallic behavior.
• Placing diamond at a low Eg conflicts with its insulating nature.

Common Pitfalls:

Confusing indirect vs. direct gaps; the magnitude still orders as diamond > Si > Ge > Sn ≈ Pb.

Final Answer:

A-1, B-2, C-3, D-4, E-5