There are two kinds of electrical charge—positive and negative.
An object that gains electrons has a negative charge.
An object that loses electrons has a positive charge.
Two charges of the same kind push each other apart. We say that they repel each other.
Two charges of different kinds pull each other together. We say that they attract each other.
A strip of paper can show you how charges of the same kind repel each other. Try this experiment when the weather is dry and not humid.
1. Stroke the strip of newspaper about 20 times with the piece of cloth.
2. Place the newspaper across a plastic ruler and lift up the ruler.
3. What can happen?
What does happen?
Explain.
Try combing your hair quickly, and then holding the comb near your hair.
Your hair stands on end!
When you combed your hair, electrons rubbed off the hair onto the comb.
This set up an electrical charge. The comb gained extra electrons and so had a negative charge.
Your hair lost some electrons and so had a positive charge.
Your hair rose towards the comb because the positive and negative charges attracted each other.
Lightning happens when positive and negative charges move towards each other through the air.
They make an electric current that causes a spark.
This spark is the flash of lightning you see during a storm.
1. Before the storm, raindrops and ice particles inside the cloud contain equal numbers of positive and negative charges.
2. As the storm begins, the rain and ice particles inside the cloud bang into each other and the charges are forced apart.
3. Most of the positive charges rise to the top of the cloud and most of the negative charges fall to the bottom.
An object that gains electrons has a negative charge.
An object that loses electrons has a positive charge.
Two charges of the same kind push each other apart. We say that they repel each other.
Two charges of different kinds pull each other together. We say that they attract each other.
Electron charges experiment:
You will need:- a strip of newspaper 12 inches (30 centimeters) x 2 inches (5 centimeters)
- apiece of wool cloth
- a plastic ruler
A strip of paper can show you how charges of the same kind repel each other. Try this experiment when the weather is dry and not humid.
1. Stroke the strip of newspaper about 20 times with the piece of cloth.
2. Place the newspaper across a plastic ruler and lift up the ruler.
3. What can happen?
What does happen?
Explain.
Your hair stands on end!
When you combed your hair, electrons rubbed off the hair onto the comb.
This set up an electrical charge. The comb gained extra electrons and so had a negative charge.
Your hair lost some electrons and so had a positive charge.
Your hair rose towards the comb because the positive and negative charges attracted each other.
Where does lightning come from?
Lightning happens when positive and negative charges move towards each other through the air.
They make an electric current that causes a spark.
This spark is the flash of lightning you see during a storm.
4. Lightning can occurwhen the negative charges from the cloud meet positive charges rising from the ground. There are also other types of lightning.
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