Water droplets rub against each other during a storm. Every drop becomes charged with a tiny bit of electricity, either positive or negative. Updrafts of wind carry the positively charged particles (small ice particles) to the top of the cloud and negatively charged particles (large water droplets) to the bottom of the cloud. Since there are billions of droplets in a cloud, a cloud carries a huge charge of electricity. When the negative part of a cloud moves near the positive part of another cloud or vice versa, electricity in the form of lightning, jumps from the negative part of a cloud to the postive part of another. Since the earth is positively charged during storms, lightning sometimes jumps from a cloud to the earth.

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