Explain oxidation to your kid with this simple shiny coin experiment 

More often than not, scientific concepts are best understood when explained in a practical way. Mere theory is not always the most engaging approach to learning science, and this holds true especially for kids. Helping your kids understand science through simple DIY experiments is one of the most effective and fun ways to help your kids not only comprehend a concept, but to also learn how to break it down using simple logic.  

Old coins, after years of circulation, often get tarnished. Here is a short and sweet DIY experiment that you can conduct at home using then to explain the concept of oxidation of methods to your kid. An added bonus: it will help you convert old, dirty coins lying around the house into shiny, new-looking ones.  

What you will need  

• 2 old, tarnished copper coins 
• 2 paper cups  
• Vinegar 
• Dish soap 
• Paper towels 
• Any other liquids available at home such as soda, ketchup, juice, etc. 

Step-by-step guide 
Gather all the materials and have your school goer to start the experiment. Here are the steps. Help him follow these. 

• Make a guess about which liquid will make the coins the shiniest. 
• Then, place each coin into a separate paper cup. In one of the cups, pour some vinegar. Similarly, pour dish soap into the other cup with the second coin. Make sure that both the liquids totally cover the coins. 
• Let them rest like that for 10 minutes. 
• After 10 minutes have passed, retrieve the coins from the cup and rinse them with water. 
• Dry them off using a paper towel. 
• Compare both the coins and see which one is cleaner. Remember to be careful as to not mix them up! 
• Repeat the same steps using some other liquids as well and record your observations. 

What exactly is happening in this experiment? 
This experiment demonstrates how some liquids are more effective when it comes to oxidation. Essentially, oxidation is a chemical process in which a certain substance changes as a consequence of being exposed to oxygen for a long period of time. The reason why the copper coins, which at one point may have been shiny and brand new, turned dull and dark over the years as a result of being exposed to oxygen. The copper and oxygen combine to form copper oxides which leave the coin tarnished. 

In the first cup, where vinegar was poured, the coin emerged looking new and shiny. This is because the acetic acid in the vinegar dissolved the chemicals. However, dish soap, although great for cleaning other things, could not achieve the same as it does not have the ability to target the copper oxide effectively.