Electricity and science
Always see it in English
1. Balloons and static electricity
Inflate a balloon, tie and rub it several times on a piece of felt or a wool sweater.
Move it closer to the ceiling and magic! The balloon "sticks" to the ceiling. It's a way of showing children the power of static electricity.
2. Balloon, hair and static electricity
For this trick, we'll need a balloon again. Again, rub it against a piece of felt or woollen fabric and then pass it through your hair... you'll see how your hair comes to life!
This is another example of static electricity that will surprise little apprentices.
3. Experiments in the kitchen
If you can't find a balloon, you may have a jar of clear glass, a plastic spoon, a little salt and some pepper in your pantry.
Mix salt and pepper inside the jar and prepare to separate them thanks to the static electricity.
It's very easy: take the plastic spoon, rub it against your clothes or hair and pay attention to what happens to the spoon. If you look, both the salt and pepper will be attracted by the spoon, which is loaded with energy, but only the pepper will become "stuck".
4. Crepe paper and a live snake
This experiment is more fun, but requires an ingredient that we may not have at home (but it is easy to find in any stationery store): Crepe paper, also known as China paper.
Apart from that, you need pencils or markers, scissors, a plastic ruler and a garment of wool.
Draw a snake on the paper and cut it out. Then, rub the ruler against the woollen garment to create an electrical charge. The ruler will attract the paper snake, which, as it is very light, will rise from the table.
Why do these things happen?
- For adults:the material is made up of atoms. And atoms are composed of protons, neutrons and electrons. Electrons revolve around a nucleus formed by protons and neutrons. If we draw two materials close together, electrons usually jump from one to the other. There are materials that, on losing electrons, are left with positive charge (hair, wool or glass) and materials that are left with negative charge (balloon, cellophane, soft-drink bottles). Materials with an opposite load will be attracted, whilst those with the same load will be repelled. How does this process differ from the electricity that illuminates our bulbs? In the fact that the electron flux that has been established is not constant, given that the electron transfer occurs only while there is friction. On the other hand, the electricity in our bulbs depends on a constant flux of electrons that uses different conductive materials.
- For children: we need to tell them, in a simple manner, that electrons are invisible and jump from one material to another. Opposites attract: positive charge to negative charge. and likes repel. The charge depends on the material that the objects we use in each experiment are made of.
Potatoes and static electricity
For this final experiment, we put static electricity aside.
Did you know that potatoes can generate electricity? You can do it at home. You only need:
- A wooden board or a firm carton.
- A cable.
- A switch.
- A bulb socket.
- A light bulb.
- Insulating tape.
- Strong scissors or pliers (to cut the cable).
- A pair of electrodes made of different material (you can use two types of coins, any penny currency and any coin of one or two euros).
- Four or five potatoes.
Assemble a simple circuit with the potatoes. If you put the potatoes in series, you increase the voltage. If you put them in parallel, you increase the current.
Use the coins as electrodes (place one of each material on each potato). When you turn on the switch... you will see how the light bulb lights up!
Why do potatoes generate electricity?
Actually, potatoes don't generate electricity. They're not a battery nor accumulator. The energy is there, it's not a mirage, and that's why the light bulb turns on. But electricity is produced by a reduction-oxidation reaction.
The potato is, in fact, an electrolyte. If we have an electrode of copper (the coin) and another of zinc (the ascorbic acid contained in the potato) in an electrolyte, the reduction-oxidation reaction is triggered. Keep in mind that the reaction will last as long as the electrolyte solution lasts.
“If you know how to use it, you can light bulbs merely with the help of a few potatoes”
More experiments and activities
We can think of a lot more activities you can do to entertain the kids at home, and help them learn at the same time. Keep visiting our blog to discover new things to try with them.
