Macromolecules

2.1.3 Covalent compounds

2.1.5 Nanoparticles

Macromolecules

  1. Macromolecules have very high melting points since all the atoms are bonded to other atoms by strong covalent bonds
  2. Carbon atoms form many different macromolecules called allotropes

  3. Diamond

    1. In diamond, each carbon atom is bonded to four others in a rigid tetrahedral structure, so diamond is very hard

  4. Graphite

    1. In graphite, each carbon atom is bonded to three others, forming layers
    2. It is soft & slippery since the layers are free to slide over each other because there are van der Waals forces between the layers which are very weak
    3. It conducts heat and electricity since one electron from each carbon atom is delocalised, making it similar to metals

  5. Fullerenes

    1. Different fullerenes have different numbers of carbon atoms
    2. The structure of fullerenes is based on pentagonal & hexagonal rings of carbon atoms
    3. Fullerenes can be used for drug delivery into the body, in lubricants, as catalysts and in nanotubes for reinforcing materials, such as in tennis rackets