*pure elements

• A pure element


  means that every one of its atoms are the same and made of just one type of atom, eg; pure gold is made of gold atoms
• Gold

  
  

  pure gold is made up of 24 carats so 18 carat gold has 18/24 parts that are gold, whilst the rest (6 parts of the 24) is made up of other metals such as silver or copper. therefore it has a purity of 75% because...

  18/24 x 100 = 75%
• from 8 carats to 24, you can see the colour change from slightly coppery to yellow-gold.
• Silver


  is marked with the number of parts per thousand.

  so, silver marked 925 atoms silver out of 1000, and 75 atoms of other metal means the item has a purity of 92,5 % because...

  925/1000 x 100 = 92,5%
• Diamonds


  are made form the element carbon and if they an item is pure, diamonds contain no other element are are colourless and translucent (let's the light through)

  
  

  it is made of a million carbon atoms
• Diamonds with a few of the carbon atoms replaced with...

  • nitrogen =yellow diamond
  • nickel = blue diamond
  • hydrogen = green diamond