topic 5 - exam qs

• Gold is used to make jewellery. Why?

  Does not corrode as it is unreactive, It is shiny and malleable, it is expensive
• Pure gold is how many carats?

  24 carats
• Some modern spectacle frames are made of shape memory alloys. Explain why shape memory alloys are better than other alloys for making spectacle frames.


  When bent, shape memory alloys return to their original shape.
• Alloys are usually stronger than the pure metals from which they are made because they what?

  Have atoms of different sizes in their structures
• Suggest why the 1-cent coin is coated with copper.

  Copper doesn't rust or corrode and it oxidises slower and kills bacteria

  
• Silver metal is deposited on the spoon. Which half-equation represents this reaction?


  Ag+ + e → Ag