Topic 2 - Bonding, Structure, and The Properties of Matter

• What is an ionic bond between?

  Metal + non-metal
• What is a covalent bond between?

  Non-metal + non-metal
• Where are metallic bonds found?

  Metals and alloys
• What happens in ionic bonding?

  Electrons are transferred
• Describe the force in an ionic compound


  Strong electrostatic forces between oppositely charged ions in all directions
• How are giant covalent structures structured?

  Lattice
• What happens in covalent bonding?

  Electrons are shared
• What does a metallic bond consist of?

  Delocalised electrons and positive ions
• What is free to move around in a metallic bond?

  Delocalised electrons
• What is the state symbol (aq) and what is it for?

  Aqueous solution - dissolved in water
• What are some properties of ionic compounds?

  • arranged in giant ionic lattices (with lots of strong electrostatic forces)
  • high melting and boiling point
  • can conduct electricity when melted or dissolved
• Why can ionic compounds conduct electricity as a liquid but not a solid?

  Ions are free to move around and carry current
• What are some properties of polymers?

  • large molecules
  • strong covalent bonds
  • solid at room temperature (strong intermolecular forces)
• Why do giant covalent structures have very high melting points?

  Strong covalent bonds between atoms
• What are some examples of giant covalent structures?

  • diamond
  • graphite
  • graphene
• Why can metals be bent but alloys can't?

  Layers of atoms can slide over each other in metals but are interrupted by different sized atoms in alloys
• Why are metals good conductors of heat and electricity?

  • energy is transferred by delocalised electrons
  • delocalised electrons are free to carry charge
• How many covalent bonds per carbon atoms is in diamond?

  4
• How many covalent bonds per carbon atoms is in graphite?

  3
• What are some properties of diamond compared to graphite?

  • diamond is hard / graphite is soft (layers can slide over)
  • graphite can conduct electricity (unlike diamond) - delocalised electrons
• What is graphene?

  Single layer of graphite
• What is the formula for Buckminsterfullerene?

  $C_{60}$
• What are carbon nanotubes?

  Cylindrical structures made of carbon atoms
• What are carbon nanotubes used for?

  • lubricants
  • medicine (deliver drugs to the body)
  • catalysts
  • reinforcing materials (e.g. tennis rackets)
• How big are nanoparticles?

  1 - 100 nm
• Why are nanoparticles good catalysts?

  High surface area to volume ratio
• Where are nanoparticles used in cosmetics?

  Sunscreens and deodorants (no white marks)
• Why do nanoparticles make good lubricants?

  Reduced friction
• What is a disadvantage of nanoparticles?


  Toxicity
• What are some properties of simple molecules?

  • low boiling and melting point
  • can't conduct heat or electricity
• Why do simple molecules have a low boiling and melting point?

  Weak intermolecular forces
• Why can't simple molecules conduct electricity?

  Electrons are held in fixed positions so they can't move