Who can obtain the cleanest copper coin?

In Science Year 6 have been investigating copper coins and how the patina on the coins react with a range of solutions found in the kitchen. The challenge was to see who could obtain the cleanest copper coin.
The students worked scientifically to ensure that the data they collected was reliable, repeatable and valid. This included ensuring the same volume of each solution was used and that coins were left for the same amount of time.
Here we can see the solutions used and some of the fantastic results. There is also an amazing side by side comparison showing what can be achieved.
Mr Baptist has been reliably informed that Indian Tonic Water is even more effective than Coke for cleaning the coins, something he shall be exploring later.
If at any time during the coming days you find your children with little to do, have them sort through your coin jar on the hunt for any 1p or 2p coin struck before 1992. Such coins are worth more for the copper content than the face value of the coin! We could all be sitting on a veritable copper mine!