giant covalent structures

• What are giant covalent structures?

  Extensive interconnecting networks of covalently bonded atoms
• Why can carbon form giant covalent structures?

  Due to its small atomic size and ability to form 4 bonds
• What are allotropes?

  Different structural forms of an element in the same state
• What are the two allotropes of carbon with giant lattice structures?

  Diamond and graphite
• How do carbon atoms bond in diamond allotrope?

  Each forms 4 strong covalent bonds in a tetrahedral arrangement
• What is the arrangement of carbon atoms in diamond?

  Tetrahedral arrangement
• Why is diamond extremely hard?

  Due to its extensive network of strong covalent bonds
• What contributes to diamond's very high melting point?

  A huge amount of energy is needed to break bonds
• How do carbon atoms bond in graphite allotrope?

  Each forms 3 strong covalent bonds and 1 delocalized electron
• What is the structure of graphite?

  Stacked layers of hexagonal carbon arrays
• Why is graphite soft and slippery?

  Weak intermolecular forces let sheets slide over each other
• How does graphite conduct electricity?

  Delocalized electrons move through the 2D lattice
• Why does graphite have a lower density than diamond?

  Weak intermolecular forces lead to increased separation between layers
• What is the sublimation temperature of graphite compared to diamond?

  Graphite has a high sublimation temperature but lower melting point
• What are the bonding, structure, and properties of diamond and graphite?

  Diamond:

  • Bonding: 4 strong 3D covalent bonds per carbon atom
  • Structure: 3D network of tetrahedrally bonded carbon atoms
  • Properties: Extremely hard, very high melting point, good thermal conductor, electrical insulator, insoluble

  
  

  Graphite:

  • Bonding: 3 strong planar covalent bonds + 1 delocalised electron per carbon
  • Structure: Stacked 2D hexagonal carbon sheets
  • Properties: Softer, conducts electricity in layers, lower density than diamond, high sublimation temperature