Paragraph 1: Energy Bands and Semiconductor Classification

In solids, atomic energy levels split to form energy (1). The highest occupied band is the (2) band; the lowest unoccupied band is the (3) band. The forbidden energy range between them is called the (4) and is denoted (5). For conductors, $E_g$ = (6) (bands overlap). For semiconductors, $E_g$ is (7) (typically 0.1–3 eV). For insulators, $E_g$ is (8) (> 3 eV). Silicon has $E_g$ = (9) eV and germanium has $E_g$ = (10) eV.

Key: (1) bands (2) valence (3) conduction (4) band gap/energy gap (5) $E_g$ (6) zero (7) small (8) large (9) 1.1 (10) 0.67