Hi Tiger. A belated welcome to EvC.
Don't most ahteists especially scientists, make arrogant claims that there is no possibility of God and theists are all wrong and such?
Atheists do, certainly. I'm one of them, so I speak from experience.
OTOH, I don't think you're justified in lumping "scientists" and "atheists" in the same pile.
Some scientists are atheists, and
some of them make the statements you refer to. Dawkins is one that springs to mind. However, although they may not make the distinction as clear as we'd like when they make the claims, they are at that point speaking from a personal worldview/opinion, and NOT as scientists. I personally wish Dawkins inter alia would be MUCH more clear on the distinction. However, humans being what they are, I know it's difficult to separate the two.
Just my two cents.