What is an atom and how do we know?

Ever wonder how we actually know that atoms exist? Here we'll learn what atoms are and exactly how scientists went about figuring all this out. Play the Bond Breaker game here: http://www.castl.uci.edu/games/bondbreaker Read about one of the CaSTL research center's "light shrinking" experiments here: https://pubs.acs.org/doi/10.1021/acsnano.7b06022 Get the Stated Clearly "Stay Curious" t-shirt here: https://teespring.com/en/stay-curious-with-us#pid=369&cid=6513&sid=front Support Stated Clearly on Patreon: https://www.patreon.com/statedclearly Correction: In this video I state that Jabir ibn Hayyan was Arabian, but there is uncertainty about this among historians. He may have been Persian. Like many influential people of his time, his story is almost mythical, with multiple origins being found in historical writings. Also, he never used a Bunsen burner (which is what I drew him using) that wasn't invented until 1856. Jabir likely burnt wood or other solid fuels to heat his reactions.