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Period: 400 BCE to 301 BCE
Democritus
-He was one of the first atomic theorist of the fifth century
-Theorized that the “atomos” were specific to the material they were composed -
John Dalton
Developed the idea of the atomic theory -
William Crookes and the Crookes Tube
Invented the vacuum tube/crookes tube
Invented 100% ultraviolet blocking sunglass lens
Invented crookes radiometer -
Period: to
William Crookes and the Crookes Tube
-Invented the vacuum tube/crookes tube
-Invented crookes radiometer
-Invented 100% ultraviolet blocking sunglass lens -
Antoine Henri Becquerel
Discovered Radioactivity -
JJ Thomson
Discovered the electron -
Marie Curie
Discovered radium and polonium -
Ernest Rutherford
Discovered the Nucleus of the atom -
Niels Bohr
Discovered that energy is transferred only in certain well defined quantities -
Erwin Schrodinger
developed a number of fundamental results in the field of quantum theory -
R.A. Millikan
Determined the size of the charge on an electron -
James Chadwick
Discovered the Neutron