-
500 BCE
Democritus
First to propose that atoms exist -
Period: 450 BCE to
Before Democritus, After Niels Bohr
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Dalton
Developed "Dalton's Atom Theory" -
William Crookes
Discovered the element Thallium -
William Crookes
Developed and created the Crookes tube -
Antoine Henri Becquerel
He discovered radioactivity -
JJ Thomson
Discovered the electron -
Marie Curie
Discovered Polonium and Radium in 1898 while trying to investigate radioactivity in pitchblende (Uranium oxide) -
Robert Andrews (R.A.) Millikan
Discovered the charge of a single electron -
Niels Bohr
Developed the idea of quantum physics and created the Bohr Atomic Model -
Erwin Schrodinger
Developed the wave equation for quantum physics -
James Chadwick
Discovered the neutron -
Ernest Rutherford
Discovered the nucleus
