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John Dalton
He stated that elements have set proportions at the atomic level due to weight. His atomic theory consisted of 5 points; 1Elements consist of small particles named atoms. 2Atoms of a specific element are unique and identical in size, mass, and other properties. 3Atoms can neither be created nor destroyed. 4Atoms combine to form compunds. 5Chemical reactions can separate and combine atoms.
Buescher, Lee. "Atomic Structure Timeline." Atomic Structure Timeline. N.p., 2004. Web. 04 Sept. 2013. -
Michael Faraday
The discovery of cathode rays by Michael Faraday is considered to be the beginning of research into the Quantum Mechanics Model. This model is very mathematical and involves the Uncertainty Principle, stating that it is impossible to know the exact time and place of each electron. "Atomic Structure: The Quantum Mechanical Model." - For Dummies. N.p., 2013. Web. 04 Sept. 2013. -
William Crookes
Discovered and defined the properties of cathode rays, which helped to figure out where particles were located within the atoms. Also identified the first ever sample of pure helium.
"Cathode Rays." Boundless. N.p., n.d. Web. 04 Sept. 2013. -
J.J. Thomson
Thomson discoverd many things in regards to atomic theory; first, cathode rays are negatively charged particle, second, the identification of the electron, and last, found the first evidence for isotopes of a stable elements. His model was called the Plum Pudding Model because it consisted of electrons just floating in a big positive stew.
Villenueva, John. "Plum Pudding Model." Universe Today RSS. Universe Today, 7 Aug. 2009. Web. 04 Sept. 2013. -
Ernest Rutherford
This man, known for being the first to successfully split an atom, was the one who established a nucleus of an atom, with the electrons outside it. He created his model from the Gold Foil Experiment; he shot alpha particles through the atoms, when they bounced in different directions he knew there was a center. Buescher, Lee. "Atomic Structure Timeline." Atomic Structure Timeline. N.p., 2004. Web. 04 Sept. 2013. -
Niels Bohr
His greatest contribution to the atomic theory was his atomic model (Which won him a Nobel Prize); a postively charged nucleus with negative electrons circling the nuclues in separate shells.
"The Nobel Prize in Physics 1922". Nobelprize.org. Nobel Media AB 2013. Web. 4 Sep 2013. http://www.nobelprize.org/nobel_prizes/physics/laureates/1922/
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James Chadwick
One of the more prominent workers on the Manhattan Project, Chadwick is attributed with discovering the neutron
"Atomic Theory Timeline." Atomic Theory Timeline. Soft Schools, n.d. Web. 04 Sept. 2013.
