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Said that atoms were small and hard, are made of a single material, are always moving, and join together.
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Believed in 5 elements, earth, wind, water, fire, and ether, and believed that they made up everything.
Images: http://no-pedia.com/aristotle.html, http://image.shutterstock.com/display_pic_with_logo/381733/381733,1326132509,3/stock-vector-the-four-elements-of-nature-air-earth-fire-water-92339143.jpg -
Said that atoms make up everything and cannot be created, destroyed, or split, and that the same types of atoms are identical, and other types are different. Also said that atoms form different substances, and chemical reactions rearrange atoms in compounds
[https://encrypted-tbn2.gstatic.com/images?q=tbn:ANd9GcTZWVqEKiANj5n9TVuvOPmu2vEwJc3qdLg6WI6CIAqW5Hy0cUyK]
Image: https://commons.wikimedia.org/wiki/File:Coypel_Democritus.jpg, http://www.google.com/url?sa=i&source=images&cd=&docid=h-7AqvvbG -
Used a glass tube with electrodes to see the path of electricity, and discovered that electrons have mass, negative charge, and that they travel in straight lines
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Created the first model of the Periodic Table of the Elements. While it did not contain all elements, it is what we work off of today.
[www.wikipedia.com/wiki/dmitri_mendeleev]
Image:http://scientistsinformation.blogspot.com/2011/01/dmitri-mendeleev-1834-1907.html, http://www.bpc.edu/mathscience/chemistry/history_of_the_periodic_table.html -
Bohr was a Danish physicist who created the common Bohr Model. He made heavy contributions to everyday knowledge of atomic structure and quantum theory. http://en.wikipedia.org/wiki/Niels_Bohr
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1887 - 1961 Schrodinger was an Austrian physicist who contributed quite a bit to quantum physics and mechanics. His quantum model allowed people to calculate where electrons might appear. Shrödinger is also well known for his experiment, "Shrödinger's cat". http://upload.wikimedia.org/wikipedia/commons/1/1f/Schrodinger.jpg
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Thomson held a magnet to the Crooke’s tube, bending the light, showing that there were negative particles because they were attracted to the positive magnet. These particles were caled electrons. He created the plum-pudding model, because there were negative electrons spread throughout a positive field.
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Worked on the first nuclear reactor, and made heavy contributions to the quantum theory, particle and nuclear physics. Also known as the “father of the atomic bomb”. http://en.wikipedia.org/wiki/Enrico_Fermi
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Einstein's Brownian motion theory allowed scientists to find the average motion of a liquid. It also allowed scientists to find the size of atoms, verifying their existence.
[http://ansnuclearcafe.org/2012/03/20/albert-einstein-and-the-most-elemental-atomic-theory/]
Image: https://en.wikipedia.org/wiki/Albert_Einstein,https://upload.wikimedia.org/wikipedia/commons/thumb/e/e2/Stylised_Lithium_Atom.png/200px-Stylised_Lithium_Atom.png -
Created the nuclear model, which had a positive nucleus and a negative field around it. He also said that the nucleus was a lot larger than the electrons in the negative field. He found this by firing particles at a thin gold plate, and watching the particles bounce back from the nucleus.
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Developed the concept of the Atomic Number, which we use regularly today. http://en.wikipedia.org/wiki/Henry_Moseley
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Sprayed water and oil on ionized plates, and found that atoms that touched electrons floated up. Then was certain that electrons were 1000 times smaller than atoms(Thompson’s theory)
http://library.thinkquest.org/C006669/data/Chem/atomic/development.html -
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Submitted 3 papers on a new neutron/proton model of the nucleus. Found that electrons do not move in set paths, which was part of his uncertainty principle. [wikipedia, the-history-of -the -atom.wikispaces.com]
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Chadwick - 1932 Chadwick discovered neutrons by doing the joilot-curie experiment
