Explain the working mechanism of thunder storm. Why does it occur?

Explanation

Thunderstorm is characterized by the presence of lightning and thunder. It occurs in cloud. Thunderstorms result from the rapid upward movement of warm, moist air, sometimes along a front. On reaching the sky and further moving higher, cools and condenses and forms cloud. These clouds can reach upto a height of 20 kilometers. Lighter, positively-charged particles form at the top of the cloud. Heavier, negativelycharged particles sink to the bottom of the cloud. When the positive and negative charges grow large enough, a giant spark - lightning occurs between the two charges within the cloud.