Structure and bonding

• What are allotropes of carbon?

  Different forms of the same element
• Why do simple molecules have low melting and boiling points?

  Weak intermolecular forces require less heat to break
• Why can't simple molecules conduct electricity?

  They have no free or charged electrons
• What is the shape of diamond?

  Pyramid-like structure
• How are the particles in diamond held together?

  Most bonded by four covalent bonds
• What type of structure does diamond have?

  3D lattice structure
• Why is diamond very hard?

  Due to its rigid lattice structure
• Why does diamond have a very high melting point?

  Strong covalent bonds require more heat to break
• Why can't diamond conduct electricity?

  It has no free electrons or charged ions
• How many atoms is each carbon atom in graphite connected to?

  Around three atoms
• What shape do the carbon atoms in graphite form?

  Hexagonal shape
• What type of structure does graphite have?

  Lattice structure
• Why is graphite soft and slippery?

  Layers can slide over each other
• Why can graphite conduct electricity?

  It has free electrons between layers
• Why does graphite have a high melting point?

  More heat is needed to break bonds
• What are fullerenes?

  Spheres of carbon atoms
• What is the molecular formula of buckminsterfullerene?

  C$60$
• Name two uses of fullerenes.

  Deliver medicine and act as catalysts
• What is the structure of graphene?

  • Made of hexagons
  • Arranged in a lattice structure
  • Strong covalent bonds
  • One single layer (one atom thick)
  • Can conduct electricity
• What are the properties of diamond?

  • Very hard due to rigid lattice structure
  • Very high melting point due to strong covalent bonds
  • Cannot conduct electricity due to no free electrons
• What are the properties of graphite?

  • Soft and slippery due to layers sliding
  • High melting point due to strong bonds
  • Can conduct electricity due to free electrons
• What are the properties of buckyballs (fullerenes)?

  • Spherical shape
  • Each carbon connected to three others
  • Low melting point due to weak intermolecular forces
  • Soft and slippery due to layers sliding