How a lighting make in clouds

Lightning is an electric current. Within a thundercloud way up in the sky, many small bits of ice (frozen raindrops) bump into each other as they move around in the air. All of those collisions create an electric charge. After a while, the whole cloud fills up with electrical charges. Lightning is caused by electricity moving in between clouds or between the clouds and the ground. The electricity is formed when ice and water particles move around rapidly inside the clouds. As the particles move they become oppositely charged and they separate.

• During a thunderstorm, the air currents move upward and water droplets move downward. These movements take at very fast pace and it results in separation of charges in the clouds.
• The positive charges accumulate at the upper edges of the clouds and the negative charges accumulate at the lower edges of the clouds. Scientists are yet to understand the exact reason for this.
• At the same time, the ground becomes positively charged.
• Air is a bad conductor of electricity under normal circumstances. But when the amount of charge becomes too much in the clouds, the air is not in a position to hold on to this charge. As a result, the electric charge is transferred to the ground. This appears like a bright streak of light across the sky; which lasts for a few seconds.