Allotropes and Structures (e.g., carbon allotropes, crystalline Si)
Start with the big picture
The lesson surveys carbon allotropes through their bonding and dimensionality. Diamond forms a tetrahedral sp³ network, while graphite consists of stacked sp² sheets; graphene is a single sheet, and fullerenes and carbon nanotubes form cage-like or cylindrical structures. Amorphous carbon, lonsdaleite, and linear carbon-chain forms extend the comparison. Silicon is considered through its stable diamond-cubic structure, metastable hexagonal form, and hydrogenated amorphous network. Across these examples, attention to bonding, lattice arrangement, and dimensional structure helps explain differences in electrical, thermal, mechanical, and optical behavior. The topic also introduces related Group 14 headings, including germanium allotropes and tin allotropy.
What you'll learn
- Compare the bonding and structures of diamond, graphite, graphene, fullerenes, and carbon nanotubes.
- Relate carbon allotrope structure to selected mechanical, electrical, and thermal properties.
- Distinguish crystalline, hexagonal, and amorphous forms of silicon.
- Identify linear carbon-chain forms and their connection to carbyne chemistry.
Continue your study
Work through the complete notes and reinforce the topic with the study tools available in the full lesson.
