Atoms...

Atoms... Pt. 2

Theory

Democritus proposed (around 440 BC)...

Aristotle disagrees. He thought (around mid 300 BC, after Democritus)...

about 2000 years have passed.
What are combined elements with a constant mass ration called?

Dalton’s Theory Stated...

So, is the atom really the smallest particle ?

Thompson experimented with the cathode ray tube and discovered...

A Few Years Later...

Niels Bohr

Electron Clouds and Current Theory

Chadwick...1932

History of the periodic table...