Magnetic Fruit - Science Experiment for Kids

Do you know most of the fruit we eat every day will have some magnetic trait, being repelled by the magnet? This experiment, Magnetic Fruit is a super fun activity for the children. The required materials can be found in every home.

Age: 3+          Time: <10mins

 Safety 

1. Beware of children swallowing the magnet.
2. Do not eat the fruit used in this experiment.
3. Adult supervision.

 Materials List 

• Support stand
• Grape (Apple, tomato)
• Rope
• Neodymium magnet
• Wooden stick

 Instruction 

Step 1/3 –Tie or one end of the rope to the middle of the stick and the other end to the support stand. (ensuring the straw can rotate freely in space.)

Step 2/3 – Slide two grapes onto each end of the stick. Adjust the position of the rope and grapes so two ends are balanced. try pushing the grapes further onto the ends of the straw to balance two ends.

Step 3/3 – Hold a magnet near a grape, but do not touch the grape. The grape will be repelled by the magnet and begin to move slowly away. There is no difference between the two poles of the magnet—evidence of diamagnetism!

 Troubleshooting 

Why my grape did not move?
—It can be that the magnetic field of the magnet is too weak, the rope is not soft enough to spin or the fruit is too heavy.

 Scientific Description 

The grape is rich in Diamagnetic materials. Diamagnetic materials are repelled by both poles of a magnet, as you saw, in this experiment, the movement of the grape. Grapes contain diamagnetic substances, so put the magnets close to the grapes to push the grapes away.  When the magnet is near the grape, an electric current is generated in the atoms of the grape that makes them magnetic in a way that will repel the approaching magnet. This is what Lenz's law tells us.

 Extensions 

In addition to the grapes, many fruits else share this trait? Like apple, tomato, and so on. You can try them out or do some fruit magnet research.