Silica ( Silicon dioxide )

• Every silicon atom is covalently bonded to four

  oxygen atoms, every oxygen atom is covalently

  bonded to two silicon atoms and has a similar structure to diamond
• There are lots of strong covalent bonds so have high melting points as a lot of energy is required to overcome these bonds
• Silica do not conduct electricity as they have no free / delocalised electrons
• This is the Silicon dioxide structure