What cause lightning during a thunderstorm?

Answer 1

Since lightning is an electrical current, normally in a thunderstorm, little pieces of ice way up in the cloud collide together fast and hard, making an electrical charge, which then eventually makes an electrical current that is known as lightning.

Answer 2

Lightning is caused by water falling through different clouds, building up a electrical difference between layers. When the potential difference becomes too great, eletrons travel from the ground up to the layers, or between the layers in a giant spark. This is lightning.

Answer 3

Lightning is caused by the buildup of electrical charges within a thunderstorm. When the charge difference between the clouds and the ground becomes large enough, a sudden discharge of electricity occurs in the form of lightning. The rapid heating and expansion of air around the lightning bolt create the sound we hear as thunder.