oh come on, you're not seriously believing that chemtrail crap, aren't you?!?
why not start using your god given intelligence (if available...) and roughly calculate how much mass of the chemicals you would need to produce any significant chemical trail that is visible from the ground, over a peroid of a few hours. Then go and look up the mass figures of the popular commercial aircrafts and you might even be able to answer the question by yourself...
Why do people believe everything they read on the internet, i really don't get it...