Disappearing Coin | STEM Activity for Kids

Magicians make the coin disappear using some trick while in this Disappearing Coin, we will teach you to make the coin disappear using science. All you need is just a coin and a glass of water.

Age: 3+        Time: <10min

 Safety

1. Be careful with the fragile glass.

2. Accompanying parents.

 Materials Lists 

• Coin
• Water
• Glass jar (or other transparent containers)

 Instruction 

Step 1/2 – Place a coin on the table and put the glass jar on it.

Step 2/2 – Pour some water in the cup and you will find the coin disappears under the glass jar if you see the coin through the side of the glass jar.

 Troubleshooting 

Why I still can see my coin?

Make sure the glass jar is fully filled with water and you look at the coin horizontally through the glass jar.

 Scientific explanation 

It is all about the refraction of light. We can see stuff because the light from the stuff runs into our eyes. When you poured water into the glass, the light from the coin is bending because of the water and it will fail to run into our eyes. Thus, we can not see the coin. But if we looking from the top, we can see the coin. Why? It is because although the light is bending, the bent light can still reach our eyes so we can see it. In our daily life, The part of the item in the water bent is because of the light refraction too.

 Extensions 

You can hind the coin under a glass of water at first and show your kids that there is nothing except a glass of water. Then you lift the glass and show your kids the coin. You will definitely get a WOW.