Electricity is all around us. We can see it as lightning in the sky, and we can use it as we power the many electrical devices in our homes. It is even present in our own bodies as the neurons in our brains fire off electrical impulses, resulting in the messages that cause our muscles to move. Electricity is the physical manifestation of the very thoughts we think.
Electricity is everywhere, but how does it work? To find out, we have to get to the very foundation of everything; we have to begin at the atom. Atoms are comprised of 3 basic units: the proton, the neutron, and the electron. Each atom contains the same number of each particle. A helium atom contains 2 protons, 2 neutrons, and 2 electrons, while a carbon atom contains 6 protons, 6 neutrons, and 6 electrons. The proton has a positive charge, and is held in the nucleus along with the neutron, which carries a neutral charge. The electron has a negative charge, and is located outside of the nucleus, in the electron cloud.
|A model of an atom. Note the nucleus and the electron cloud.|
Photo Credit: EHow
The electron cloud contains many layers, depending on how many electrons the atom has. Electrons that are located in the layer closest to the nucleus have a stronger bond than those that are located in the outer shell. Electrons that are the furthest out can occasionally be knocked loose by another force acting upon them. The loss of the electron creates a positively charged ion (an ion is an atom with an unequal number of electrons and protons), which is then attracted to a negative charged ion in order to regain the lost electron.
We can easily demonstrate how this happens by rubbing a balloon on a piece of clothing or a carpet. As you use force on the balloon against the material, you will notice a static charge begin to build up. This is because the force of rubbing the balloon has knocked some of the electrons off of the atoms that make up the balloon. This has created a positive charge on the balloon, and a negative charge on the material. You will notice that the balloon is likely to stick to the surface of that material as the atoms seek to neutralize the charge.
There are some really fun and interesting demonstrations you can do to show just how these charges cause the objects (and the atoms within) to interact with each other. A great place to start would be to give your kids the opportunity to really grasp the concept of an atom. I've found that the best way to understand an atom is to BE the atom!
ATOMS IN MOTION!
1. A group of kids! (Or just you and your kid(s).)
2. Construction paper
1. Cut out an equal number of positive signs, negative signs, and equal signs. These signs will represent the charges in an atom.
2. Assign one child to be the proton, one to be the neutron, and one to be the electron. The kids will need to hold on to their corresponding charge symbol. The proton and neutron will stand next to each other, clumped together as the nucleus. The electron is free to run circles around them as they orbit in their electron cloud. The kids may want to take turns with this one, as being the electron is really fun!
3. Create a force to knock the electron off its course. This will leave the atom with a positive charge, and wherever the electron ends up with an extra negative charge. You can then push them back together to neutralize the charge.
Note: If you have a larger group of kids, say in a classroom or at the park, you can split them into several groups of atoms! You can create a helium atom, with 2 protons, 2 neutrons, and 2 electrons, or you could create a Lithium atom with 3 of each particle, the element is up to you and how many kids you have in your group.
If you have two atoms, you can have one atom lose an electron to gain a positive charge, while the other atom gains the electron and with it, a negative charge. You can then push them towards each other, and have the electron run back to its previous atom, thus neutralizing the charge.
Aside from being a very fun and giggly exercise, this provides a very clear demonstration of how atoms work, and how electricity is created. The knocking off of the electron has sent it down an "electric path", resulting in the release of energy we know as electricity!
Once the kids have an understanding as to how electron transfers create electricity, it's time to let them play! The following demonstrations require balloons, a comb, and a surface to rub the items on to generate a static charge. Some atoms have stronger atomic bonds than others, so you may find that you'll get different results with different materials.
1. Inflated Balloon
1. Vigorously rub the balloon on your head for ten seconds.
2. Slowly pull the balloon away from your head.
3. Observe what happens when you pull the balloon away. Using what you've learned about static electricity, can you explain what is happening?
THE AMAZING WATER BENDER!
One fun way you can demonstrate charges moving together (opposites attract!) is by bending water. We used both a comb and a balloon for this demonstration, and the difference in effect was really neat.
1. Running water out of a sink.
2. A comb
3. A balloon
4. A head of hair
5. Wool or fleece (I found that fleece built up quite a charge)
1. Turn on the faucet of your sink so that you have a very thin stream of water. I found that turning it just past a drip works best. You want a steady stream but it needs to be as thin as possible.
2. Take your comb and run it through your hair 10-15 times. This will allow a static charge to build.
3. Take your comb and move the bristles close to the running stream of water. You should see the water start to move!
4. Try it with a balloon. What happens? Does anything change if your materials get wet?
|Note: This is not the actual effect of this demonstration.|
The lighting was much too dim for a picture, but the real effect is still cool!
POWER A LIGHT WITHOUT THE SWITCH!
You can also use static electricity to power on lights without even turning on the switch! This is a really impressive demonstration of the power of electricity.
2. Any material that will build a decent charge. I found that carpet and fleece work the best, but you can even build a charge by simply using the hair on your head.
3. A fluorescent light bulb.
1. Rub your balloon vigorously against your chosen material to create a static charge.
2. Carefully pick up your fluorescent light bulb and bring it to the balloon.
3. Observe what happens.
4. Experiment! Can you make the effect stronger? Do different materials build a better charge with the balloon? What happens if you place something between the balloon and the light?
IT TAKES TWO!
What happens if you place two objects with a similar charge right next to each other?
1. Two inflated balloons
4. A surface on which to rub the balloons (carpet, wool, fleece)
1. Cut a length of string to tie to each balloon.
2. Bring your balloons together until they are approximately 1" apart.
3. Tie the strings together so that the balloons will stay as close to each other as possible.
4. Vigorously rub both balloons on your chosen surface until you have generated a sufficient static charge.
5. Let the balloons go, and observe what happens.
6. Experiment! Is the effect any different if you place your hand between the balloons? A piece of clothing? Aluminum foil?
Working with static electricity provides a fun and safe way of learning about how electricity works. I have a much better grasp on what happens when I turn on a light, power on a fan, or even when my daughter and I share a spark after she goes down a slide. Electricity is everywhere, and it's fun to learn about it and play with! I have a feeling that this will give us a nice foundation of understanding as we knock a bunch of electrons around in order to see what will happen.