Different forms of carbon:

Cards (9)

  • Allotropes are different forms of the same element
  • Small covalent molecules have low melting/boiling points due to weak intermolecular forces
  • Giant covalent molecules are always solids at room temperature with high melting/boiling points because of millions of strong covalent bonds
  • Diamond:
    • Made from carbon
    • Each carbon atom is joined to four other carbon atoms by strong covalent bonds
    • Cannot conduct electricity because electrons do not carry a charge
  • Silicon dioxide:
    • Elements silicon and oxygen are covalently bonded
    • Has a high melting/boiling point due to many strong covalent bonds
  • Graphite:
    • Made from carbon
    • Each carbon atom forms 3 covalent bonds with other carbon atoms
    • Hexagonal rings formed by carbon atoms
    • Soft and slippery due to layers with no covalent bonds allowing atoms to slide
    • Good conductor of heat and electricity due to delocalized electrons
  • Graphene:
    • Single layer of graphite, one atom thick
    • Extremely strong
    • Good conductor of electricity due to delocalized electrons
  • Fullerenes:
    • Molecules of carbon atoms with hollow shapes
    • Usually have hexagonal rings with rings of 5 or 7 carbon atoms
    • Used for catalysts to speed up chemical reactions
    • Lubricating properties to prevent moving parts from smashing together
  • Carbon Nanotubes:
    • Fullerenes shaped into long cylinders
    • Can be stretched without breaking
    • Good conductor of heat and electricity