oct 10, 1897 - JJ Thomson
Description:
Summary: Discovered electron.
Experiment: Cathode ray experiment:
How did it work?:
A negatively charged cathode sent out invisible rays that glow when they come into contact with some gases. These were seen to travel straight but would bounce of negatively charged pads. However, positively charged pads attracted them. This suggested that these rays were not radiation at all, but small, negatively charged particles.
What changes did this make to the atomic model? Why is this important?:
Electrons were added to the model. However, the charge is still evenly distributed through the atom. This is important because it is the first evidence of sub-atomic particles.
What was this model called?:
The Plum Pudding Model.
Pictures:
Top:Portrait
Mid: Cathode ray experiment
Bottom: Plum Pudding model
Added to timeline:
History of the atom
Date:
Images:
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