Discipline: Chemistry
Age Range: 5+ (with adult supervision)
Estimated Time: 10 minutes
What you need: Dull pennies, vinegar, table salt, bowl, spoon, and water
Instructions: Have you ever wondered why pennies lose their shine and start to look dull and dirty? This happens because pennies are made up of copper. When copper touches oxygen, it begins a chemical reaction called oxidation, which makes pennies look dull. There’s another simple chemical reaction that can make dull pennies look shiny and new again! Just follow these steps to try it at home:
Ask an adult to help you mix one teaspoon of salt into ¼ cup of vinegar.
Place a dull penny in the mixture. Count slowly as you stir the penny around in the vinegar mixture.
Watch as the penny becomes shiny right before your eyes! How many seconds did it take for the penny to look shiny and new?
Remove the penny from the vinegar mixture and rinse with water.
Watch your penny sparkle!
This works because vinegar is an acid, which is a type of liquid that can be used to break down other materials (such as the copper oxide formed on your penny from oxidation). Try using another acid, like lemon juice or hot sauce, and see if it has the same result!
