chemical bonding and structure + properties of materials

• Covalent compound and its properties

  • Formed by sharing of electrons between non metals
  • Has a simple molecular structure
  • Usually exists as a gas or liquid at room temperature
  • Volatile
  • Has low melting and boiling point
  • Soluble in organic solvent
  • Insoluble in water
  • Unable to conduct electricity in any state
  • Only exception to the previous condition is hydrogen chloride in aqueous state as it is able to conduct electricity in that state

   
• Ionic compound and its properties

  • Formed by transfer of electrons from metal to non-metal
  • Non metal atoms will gain electron(s) to form a negatively charged ion (anions)
  • Metal atoms will lose electron(s) to form a positively charged ion (cations)
  • hold atoms together in a giant lattice structure
  • Solids at room temperature
  • Non volatile
  • High melting and boiling point
  • Soluble in water
  • Insoluble in  organic solvent
  • Can conduct electricity in aqueous and molten state
  • Cannot conduct electricity in solid state
• Properties of graphite

  • High melting and boiling point
  • Conducts electricity
  • Insoluble in water
  • Soft and slippery
  • Used for pencil and heavy machine lubricants

   
• Properties of diamond

  High melting and boiling point

  Cannot conduct electricity

  Insoluble in water

  Very hard

  Used for drill tips or polishing