C2 - Covalent bonding + molecules

• What is covalent bonding?

  • Involves the sharing of electrons between two or more atoms
  • Occurs between non-metals
• What is a main property of giant covalent structures?

  High melting and boiling points

  • Lots of energy needed to overcome the strong covalent bonds
• What are the properties of small covalent molecules?

  Do not conduct electricity

  • Do not have an overall electric charge

  Low melting and boiling points

  • Gases or liquids at room temperature
• Oxygen has a low melting point.

  Explain why. [3 marks]

  • Oxygen is a simple molecule
  • Weak intermolecular forces between the molecules
  • Small amount of energy needed to overcome these forces