How Did Scientists Develop and Validate the Atomic Model?

[Itry]

I'm reading a book about electricity (Teach Yourself Electricity and Electronics) because I want to know more about electricity. So I started reading this book, seems well written, but right at the beginning I couldn't figure out what is meant. And so I had to stop. It's talking about atoms and says "All matter consists of countless tiny particles in constant motion." OK, while I am willing to accept that, how do scientists know this, I mean where did they see this?

 

[kuruman]

OK, while I am willing to accept that, how do scientists know this, I mean where did they see this?

It's not "where" scientists saw this but "how" scientists proceeded to develop and refine the atomic model following the scientific method of forming and validating hypotheses. You might wish to read about the history of the atomic theory here.
https://en.wikipedia.org/wiki/History_of_atomic_theory