Physical explanation for thunder

[ash_win]

folks,
when i was small,the explanation for thunder,given to me was that when two clouds clash lightning is produced and due to the collision thunder is heard

but now someone told me that thunder is caused when two clouds clash charges are neutralised and large amount of energy is liberated which appears in the form of lightning and during lightning the air get ionised and a large vacuum is created and after sometime air fills in the empty space with a rumbling noice which appears as the thunder

is this the correct explanation of thunder...if not please explain

thank you

 

[pixel01]

I think sparks between clouds are enomous and very hot, probably millions of degrees. So the air in the region get hot too and expands suddenly creating thunders.

 

[Shooting Star]

It's best to look up a specialized site for this sort of thing.

http://www.wxdude.com/page5.html

The wikipedia page is disappointing.