polymers and giant covalent structures

• what are polymers?

  long molecule made up of repeating subunits called monomers, polymer = many units, monomer = one unit
• what are the atoms in a polymer joined by?

  strong covalent bonds
• instead of drawing out a long polymer molecule, polymers can be repressed like this:

  
• why is more energy needed to break the intermolecular forces between a polymer?

  forces are larger than between simple covalent molecules
• what state are most polymers at room temperature?

  solid
• how are all the atoms bonded in a giant covalent structure?

  strong covalent bonds
• what are the properties of giant covalent structures?

  -very high melting and boiling points, lots of energy needed to break strong covalent bonds

  -don’t conduct electricity as they don’t contain charged particles
• main examples of giant covalent structures?

  -diamond

  -graphite. -silicon dioxide
• describe a diamond structure?

  each carbon atom forms four covalent bonds in a very rigid giant covalent structure, looks like a pyramid

  
• describe a graphite structure?

  each carbon atom is bonded to three covalent bonds to create layers of hexagons, each carbon atom also has one delocalised(free)electron, layers can slide off of each other

  
• describe a silicon dioxide structure?


  sometimes called silica, this is what sand is made of, each grain of sand is one giant structure of silicon and oxygen