· kitchen cleaner
· 10 dirty copper coins
· 50ml vinegar
· a glass
· a pinch of salt
· 3cm nail
1. Put the coins into the empty glass then cover them with vinegar. Stir in the salt and leave for five minutes.
2. Meanwhile, clean the nail with kitchen cleaner and dry it carefully. It should now be very clean and bright.
3. Remove the coins from the vinegar, leaving the vinegar in the glass. What happened to the coins?
4. Drop the nail into the vinegar and leave it there for half an hour.
5. What has happened to the nail?
· The vinegar contains acid which dissolved the brown copper-based chemicals from the coins, leaving them shiny.
· These copper-based chemicals then mixed with the vinegar to make a new chemical.
· This chemical settled on the nail and turned it brown.