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Aristotle believed that atoms were not in everything, but the four elements, Fire, water, air, and earth.
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Found out mass is conserved in a chemical reaction.
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He discovered them while making experiment with cathode rays. They knocked around the electrons of atoms and attract them to a positively charged electrode
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Discovered thallium and further developed the atomic theory.
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W.K was the first to produce X-Rays and won a nobel prize for it. At first they were called "Röntgen rays"
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Henri discovered radioactivity.
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Wanted to test the electric discharge in a vaccum tube.
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As a team and couple they discovered these two elements.
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"A theory of matter and energy based on the concept of quanta, especially quantum mechanics."
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Marie found out that radioactivity doesn't depend on how atoms are arranged in molecules, but rather that it originates within the atoms themselves.
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Einstein shows how the movement of molecules in a liquid can cause the Brownian motion.
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Hans made the first successful geiger counter, it detected alpha particles and other radiations.
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His experiment helped quantify the charge of an electron. This experient contributed greatly to the atomic theory.
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Ernest's new model showed that an atom's electrons were small and concentrated instead of being spread out. This helped him discover protons.
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He proposed this idea based on the quantum theory. "Electrons should move around the nucleus but only in prescribed orbits. When jumping from one orbit to another with lower energy, a light quantum is emitted"
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Erwin used mathematical equations to describe the likelihood of finding an electron in a certain position.
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Splits an atom with his assitant Fritz Strassman and tells Lise Meitner
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Splitting the atom. Otto Hahn and Fritz Stassman helped discover it.
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Plutonium-239 was shown as being able to split when slow neutrons were used, this was seen as a good material for making nuclear bombs.
