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460
Democritus
460 BC
Democritus came up with the idea and name of the atom; although, his ideas were ridiculed, even by Aristotle. -
John Dalton
1800's
John Dalton did many experiments with chemicals that all pointed to the idea that there were small particles in matter. -
J. Plucker
He built one of the first cathode-ray tubes. -
James Clerk Maxwell
James Clerk Maxwell came up with the theory of electromagnetism and found the connection between light and electromagnetic waves. -
G J Stoney
G.J. Stoney came up with the idea that electricity was comprised of negative particles he called electrons. -
Sir William Crookes
Sir William Crookes’ experiments with cathode-ray tubes led him to confirm that cathode-rays have a negative charge. -
Wilhelm Roentgen
Wilhelm Roentgen discovered x-rays. -
J. J. Thomson
J.J. Thomson discovered the electron and proposed a model for the atom. He knew that electrons were negative, so there must be something positive. He created the 'plum pudding' model. -
Einstein
Einstein found the 'photon' and came up with the 'photoelectric effect'. -
Richard Abegg
Richard Abegg found that inert gases have a “stable electron configuration.” -
Ernest Rutherford
Ernest Rutherford did an experiment were he shined Radium alpha particles through gold foil. He discovered the positively charged nucleus. -
Niels Bohr
He came up with the rules for how electrons move around the nucleus. -
H G J Moseley
H.G.J. Moseley discoveres that the number of protons in an element equals the element's atomic number. -
Francis William Aston
He identified 212 isotopes. -
James Chadwick
He discovered neutrons in the nucleus.
