jan 1, 1897 - JJ Thomson
Description:
In 1897, J.J. Thomson used a crookes tube and discovered the existence of the subatomic particle (the electron). He found these electrons to be particles which carry electrical charge. They also have a mass that is a thousand times smaller than a hydrogen atom. J.J. Thomson's conclusion to this was that are particles smaller than atoms so an atom must not be the fundamental or smallest particle.
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Atomic theory
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