Polymers and giant covalent structures

• What is a polymer made up of?


  Lots of small units linked together to form a long molecule with repeating sections.
• How are atoms in a polymer joined?

  Strong covalent bonds.
• How can you draw a polymer?


  Draw the shortest repeating section.
• How can you find the molecular formula of a polymer?


  Write the molecular formula of the repeating unit in the brackets, and put an ’n’ on the outside.
• Why are most polymers solid at room temperature?


  Large intermolecular forces means more energy is needed to break them.
• What are intermolecular forces of polymers like?


  Weak.
• What are giant covalent structures?


  Macromolecule.
• How are atoms bonded in giant covalent structures?


  Strong covalent bonds.
• Why do giant covalent structures have high melting and boiling points?


  Lots of energy is needed to break the strong covalent bonds between atoms.
• Why do most giant covalent structures not conduct electricity?


  They don’t contain charged particles.
• Which 3 giant covalent structures do I need to remember?


  Diamond, graphite, silicon dioxide.
• What is the structure of a diamond like?

  Each carbon atom forms four covalent bonds in a very rigid structure.
• What is the structure of graphite like?


  Each carbon atom forms 3 covalent bonds to create layers of hexagons. Each carbon atom also has one delocalised electron.
• What is the structure of silicon dioxide (sand) like?


  One giant structure of silicon and oxygen (per grain of sand)