SciShow
This Is Not What an Atom Looks Like
What does an atom look like? Throughout history scientists and philosophers have attempted to answer this question. As a result, they've come up with some useful models for understanding the building blocks of our universe.
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The Science Classroom: History of the Atom (Atomic Theory)
Looks at the history of models of the atom beginning with Democritus and ending with contemporary understanding of the atom. Covers all major models. [9:02]