Polishing Pennies
This Demonstration is included in a bundle of 101 Science Demonstrations & Experiments. You can find this bundle here in my TpT Store. These exciting demonstrations use mostly inexpensive materials that you can find around your home or can be easily purchased. I show how to run the demonstration, give helpful advice and explain the science concepts behind it. Many of these demonstrations can be turned into STEM projects for your students. For fun & FREE STEM Activities, click here!
Also please check out my bundle of 36 STEM Activities: STEM for the whole year!
Materials needed:
• 1/4 cup white vinegar
• 1 teaspoon salt
• water (for rinsing)
• paper towel
• dull pennies
• bowl (non-metal)
• spoon
Directions:
1. Add vinegar to the bowl.
2. Add salt to make a vinegar-salt solution.
3. Add the Pennies.
4. Stir with Spoon for about 2-3 minutes.
5. Rinse the pennies off.
The Science Behind this Experiment:
Pennies are coated in copper. Copper that has been exposed to air (oxidized) over time will become copper oxide, which makes it appear dull. So how does the vinegar – salt solution make the pennies so shiny? Vinegar is an acid (typically 5% acidic acid). Combining it with salt allows it to chemically remove the outside of the penny as it reacts with the copper oxide.
Did you like this Demonstration?
You can find 100 more of them in a resource I recently put together. Check it out here in my store.
Sample Demonstrations:
Chemistry
Combustion
Density
Electricity
Energy
Food Science
Forces and Motion
Light
Magnetism
Sound
Sublimation
