Lightning, thunder and staying safe
A flash lights the sky. Then a rumble follows. What makes each?
- Warm, wet air climbs and cools. A storm cloud grows.
- Strong winds push up and down inside the cloud. Ice and water drops rub together.
- Rubbing gives them charge. The top gets positive charge. The bottom gets negative charge.
- Too much charge forces its way through the air. Charge flows in a flash.
- The flash heats the air. The air expands fast. That is thunder.
New words
- Electric charge — rubbed things can get it. It is positive or negative.
- Lightning — a flash made when stored charge jumps. It can jump inside a cloud, between clouds, or to the ground.
- Thunder — the loud sound of air that lightning has heated.
- Lightning conductor — a metal rod on a tall building. It leads the charge into the ground.
The rule
Lightning makes the flash. Thunder is the deep sound that follows.
Air normally blocks electric charge. When charge grows very large, the air can no longer block it.
Rule: Lightning is a sudden flow of charge. It heats the air, and the hot air makes thunder.
A tall building can have a lightning conductor. The charge flows down the rod into the ground. The charge does not go through the building.
Stay safe
Lightning can start fires and can kill. When you hear thunder, go indoors. Stay in a strong building, such as a home or school. Or stay in a closed car or bus with the windows up. A tent, a shed or a bus stop is not safe. A bicycle or a bike is not safe. Stay inside for 30 minutes after the last thunder.
Indoors, keep away from windows. Do not touch taps or wires.
If you are caught outside, keep moving. Go to a strong building or a closed car. Keep away from water. Keep away from tall trees and poles. Leave hills and high open ground. Do not lie flat on the ground. Do not hold a metal-rod umbrella.
Follow a storm cloud. Pick what happens next.
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