Here’s another fun experiment with pennies. You need half a cup of vinegar and a teaspoon of salt. Mix it and put the coins in the solution. The dull ones will regain their shine. If you want to keep them shiny rinse them in water, if you want to turn them green/blue put them to dry on a paper towel without rinsing.

Experiment sheet/structure

1. The questions – What happens with the pennies when put in the solution? What if you rinse them with water or leave them to dry without rinsing?

2. Prediction – hypothesis

3. Testing & results

4. Explaination of results

Basic explanation is that coupper oxidates in contact with the oxigen in the air, the heat or salty water. The dull pennies will regain their shiness when put in this solution and rinsed. But if this acidid and salty solution is left on it oxidates and forms a protective outer layer that prevents further corrosion called patina.

5. Applicability or examples

Coupper is a good heat and electricity conductor and is widely used in wiring and pipes. It’s corrosion process is long which makes it good for roofing and gutters. Great example to mention is the Statue of Liberty which is green because is made of coupper.