Giant Covalent Structures and fullerness

• Giant covalent structures are similar to giant ionic lattices except there are no charged ions. The atoms are bonded to each other by strong covalent bonds, meaning it has very high melting and boiling points
• Giant covalent structures do not conduct electricity even when melted (except graphite, graphene and fullernes)
• Carbon can form many different molecules because carbon atoms can form four covalent bonds and bond easily to other carbon atoms to make chains and rings
• In diamond, each carbon atom forms four covalent bonds in a very rigid covalent structure. This makes diamonds really hard and a good cutting tool
• • All the strong covalent bonds in diamond take a lot of energy to break and give diamond a high melting point, which is also why it is a good cutting tool
  • It doesn’t conduct electricity because it has no free electrons or ions
• • Graphite is black and opaque but still kind of shiny
  • Each carbon atom only form three covalent bonds, creating sheets of carbon atoms which can slide over each other
• • The layers in graphite are held together weakly so they are slippery and can be rubbed off to paper to leave a black mark.
  • This also makes graphite a good lubricating material
• Since only three out of four outer electrons are used in bonds of graphite, there are a lot of delocalised electrons, which is why it conducts electricity
• • A single sheet of graphite is called graphene. Its covalent bonds make it very strong.
  • It is so thin that it is transparent and light.
  • its delocalised electrons are completely free, so it is better at conducting electricity than graphite
• Fullernes is another form of carbon. They are not giant covalent structures. They are molecules shaped like hollow balls or tubes
• Carbon atoms in fullerenes are arranged in rings. They have delocalized electrons so they can conduct electricity
• Melting and boiling points in fullernes are not as high as diamond or graphite but are still high for molecular substances
• Giant covalent structures only have covalent bonds and no intermolecular bonds, which is why they are so strong