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History of the Atomic Model - Coggle Diagram
History of the Atomic Model
John Dalton:
Date: 1808
Showed that substances always broke down into the same elements in the same proportions.
Democritus:
Proposed that everything in the world was made up of tiny particles surrounded by empty space.
Date: 440BCE
Aristotle:
Date: 5th century BCE
Disagreed completely with Democritus, saying that everything was made of earth, water, wind, and fire.
J.J. Thomson
Showed uniformly packed atoms as positive charged spheres of matter filled with negatively charged electrons.
Date: 1897
Werner Heisenberg
Concluded that it is impossible to pinpoint exactly where an electron is nor its speed.
Date: 1927
Rutherford
Discovered that atoms were filled with little particles with electrons spread out through them with most of the mass at the center, the nucleus.
Date: 1911
Niels Bohr
Discovered that electrons orbit the nucleus at fixed energies and distances.
Date: 1913