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John Dalton
Came up with the atomic theory: all matter is composed of atoms. -
Antoine Lavoisier
Provided the formula for the conservation of matter and distinguished between an element and a compound. -
William Crookes
Invented the Crookes’ tube and discovered the properties of cathode rays. -
G.J. Stoney
Proposed that electricity was made of negative particles: "electrons". -
W.K. Roentgen
Discovered x-rays while experimenting with cathode-ray tubes -
J.J. Thomson
Discovered the electron and made the plum-pudding model of the atom. -
Pierre and Marie Curie
Radioactive materials cause atoms to randomly break down and realese radiation in the form of energy and subatomic particles. -
Albert Einstein
Published the equation E=mc 2 -
Robert Millikan
Discovered the electric charge of the electron -
Neils Bohr
Stated that the electrons moved around the nucleus in successively large orbits and that atoms absorb or emit radiation only when the electrons abruptly jump into different orbits then back to the original -
Francis Aston
Discovered the existence of isotopes through the use of a mass spectrograph. -
Erwin Shroedinger
Introduced the Shroedinger Equation, a wave equation that describes the form of the probability waves that regulate the motion of small particles and how these waves are changed by external influences. -
James Chadwick
Discovered the neutron. -
Otto Hahn and Lise Meitner
Discovered nuclear fission: when the nucleus of an atom breaks up into two separate nuclei -
Ernest Rutherford
Used the results of his gold-foil experiment to establish that the nucleus was dense, tiny and positively charged. He also established that the electrons were located outside the nucleus.