Polymeters and Giant Covalent Structures

• Polymer


  A large molecule made up of many small units joined together
• Forming a polymer


  1. Lots of small units are joined together to form a long molecule

  2. All the atoms in a polymer are joined by strong covalent bonds

  3. A small part of the polymer is called the repeating unit

  4. The polymer is made up of this unit repeated over and over again
• Molecular formula of a polymer


  Write down the molecular formula of the repeating unit, put brackets around it, then put an 'n' outside
• The intermolecular forces between polymer molecules are larger than between simple covalent molecules
• More energy is needed to break the intermolecular forces in polymers, so most are solid at room temperature
• The intermolecular forces in polymers are still weaker than ionic or covalent bonds, so they generally have lower melting and boiling points than ionic or giant covalent compounds
• Giant covalent structure


  All the atoms are bonded to each other by strong covalent bonds
• Giant covalent structures


  • They have very high melting and boiling points
  • They don't contain charged particles, so they don't conduct electricity (except for a few weird exceptions such as graphite)