What causes lightning? and how is it formed?

Answer 1

http://en.wikipedia.org/wiki/Lightning

Answer 2

Lightning is caused by electrical charges in the atmosphere (due to particles, ions, etc. rubbing against each other and just the charges of the compounds in our atmosphere). It is formed when a channel of ions creates a pathway to discharge the electrical current of the atmosphere. This is cloud to ground. Then you get the return stroke (the part you actually can see) that goes from ground to cloud. This is a positive charge.

Simply: The cloud holds negative charges and tries to discharge them with the positive charges on the ground.

If you want to see a cool animation, look at the links I provided.

Answer 3

Potential difference between clouds or between a cloud and the land causes lightning.Potential difference cannot exist beyond certain level .When that level is reached,electric current starts flowing between the two oppositely charged objects in the form of arc which is called lightning.

Answer 4

is this your homework?
Lightning is an atmospheric discharge of electricity, which usually, but not always, occurs during rain storms, and frequently during volcanic eruptions or dust storms.

there are lot of research regarding how lightning is formed, if you want to know more about lightning i suggest you click my source below.:
http://en.wikipedia.org/wiki/Lightning

Answer 5

It has to do with the electricity in the ground and the electricity in the air. There are positive and negative charges.
Lightning looks like it coming from the sky But it is the positive and negative charges meeting together.

Answer 6

The static electricity, is released out of the atmosphere, from negative and positive charges.