How Lightning Occurs
Are you
scared of lightning? Most of people do. It has scary sound dan the light is
terrifying. Do you know how lightning occurs?
Lightning
is an electric current that happens in the cloud. It happens because when the
ground is hot, it heats the air above it. This warm air rises. As the air
rises, water vapour cools and forms a cloud. When air continues to rise, the
cloud gets bigger and bigger. In the tops of the clouds, temperature is below
freezing and the water vapour turns into ice.
Now, the
cloud becomes a thundercloud. Lots of small bits of ice bump into each other as
they move around. All these collisions cause a build up of electrical charge.
Eventually,
the whole cloud fills up with electrical charges. Lighter, positively charged
particles form at the top of the cloud. Heavier, negatively charged particles
sink to the bottom of the cloud.
When
the positive and negative charges grow large enough, a giant spark which we
call lightning occurs between the two charges within the cloud. This is like a
static electricity sparks you see, but much bigger.
Most
lightning happens inside a cloud, but sometimes it happens between the cloud
and the ground. A build up of positive charge builds up on the ground beneath
the cloud, attracted to the negative charge in the bottom of the cloud. The
ground's positive charge concentrates around anything that sticks up such as
trees, lightning conductors, even people. The positive charge from the ground
connects with the negative charge from the clouds and a spark of lightning
strikes.
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