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John Dalton
John Dalton gave us our first true model of an atom, and even expanded that to an atomic theory. In 1808 , Dalton published a paper that for the first time began to explain the behavior of chemicals. -
J.J Thomson
First scientist that decided that dalton's atom needed to be updated , so he proppsed a new model of the atom.His model became known as the plum pudding model -
Max Planck
used the idea of quanta (discrete units of energy) to explain hot glowing matter. -
Robert Millikan
Oil drop experiment determined the charge (e=1.602 x 10 -19 coulomb) and the mass (m = 9.11 x 10 -28 gram) of an electron. -
Marie & Pierre Curie
She and her husband Pierre also discovered the radioactive elements polonium and radium. -
Ernest Rutherford
Rutherford's planet system modl was an improvement over earilker models but it was still not complete.
he proposed that all the postive charge is concentrated in a small core in the center of a atom -
Werner Heisenberg
Proposed Principle of Indeterminancy - you can not know both the position and velocity of a particle. -
Niels Bohr
proposed a new model that would aloow the electrons to be outside the nucleus and in orbit around the nucleus. his model coupled rutherfords model with a newer concept regarding energy called quantum mechanics -
Henri Becquerel
The materialBecquerel was a double sulfate of uranium and potassium which he exposed to sunlight and placed on photographic plates wrapped in black paper.When developed, the plates revealed an image of the uranium crystals.
