Diamond/silicon dio

• What are the two giant covalent molecules discussed in this video?

  Diamond and silicon dioxide
• Why do giant covalent substances have high melting and boiling points?


  They contain millions of strong covalent bonds that require a lot of energy to break
• What is the structure of small covalent molecules compared to giant covalent substances?


  Small covalent molecules have a small number of covalent bonds
• What happens to small covalent substances when they melt or boil?


  Weak intermolecular forces are broken, requiring little energy
• What is the melting point of diamond?


  Over 3,700 °C
• Why can't diamond conduct electricity?


  All outer electrons are involved in covalent bonds, leaving no free electrons
• What elements make up silicon dioxide?


  Silicon and oxygen
• How does the structure of silicon dioxide compare to diamond?


  Both have a huge number of covalent bonds and high melting and boiling points
• What is the significance of the number of covalent bonds in giant covalent substances?


  A large number of covalent bonds contributes to their hardness and high melting points
• What are the properties of giant covalent substances?


  • Always solids at room temperature
  • High melting and boiling points
  • Extremely hard due to strong covalent bonds
  • Cannot conduct electricity
• How do you represent the structure of diamond in a diagram?

  • Carbon atoms are shown as circles
  • Covalent bonds are shown as sticks
• What is the process to melt giant covalent substances like diamond and silicon dioxide?


  1. Break all covalent bonds
  2. Requires a great deal of energy