What causes lightning?
3 answers
http://www.planet-science.com/categories/over-11s/natural-world/2012/06/what-causes-lightning.aspx
can i tell you what i think how it causes lighting
When air rises and falls within a thunderstorm, positive and negative charges form in the cloud. The bottom of the thundercloud has a negative charge, and the top has a positive charge. A flash of lightning happens when a charge becomes so strong that the air can’t stop it from jumping from the cloud to the ground, which has a positive charge. Lightning can also form inside the cloud, moving between the positively and negatively charged areas. The average flash of lightning could turn on a 100-watt light bulb for more than three months. The air near a lightning strike is hotter than the surface of the Sun.