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First to believe that everything in the universe was made up of atoms, which were microscopic and indestructible.
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Developed the atomic theory. He had 4 parts to it. 1) All matter is made of atoms. Atoms are indivisible and indestructible.
2) All atoms of a given element are identical in mass and properties.
3) Compounds are formed by a combination of two or more different kinds of atoms.
4) A chemical reaction is a rearrangement of atoms. -
Took the elements and put them into the periodic table.
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He discovered protons with the experiments he did with cathode rays which would knock electrons of atoms and attract them to a positively charged electrode.
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Discovered the electron.
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Developed quantum theory. Planck made the assumption that energy was made of individual units, or quanta. Developed the law that describes the spectral density of electromagnetic radiation emitted by a black body in thermal equilibrium at a given temperature T.
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Began a series of experiments to determine the electric charge carried by a single electron. He got his results from his oil-drop experiment in which he replaced water with oil.
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He was the first to discover that atoms have a small charged nucleus surrounded by largely empty space, and are circled by tiny electrons, which became known as the Rutherford model (or planetary model) of the atom.
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Bohr was the first to discover that electrons travel in separate orbits around the nucleus and that the number of electrons in the outer orbit determines the properties of an element.
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He took the Bohr atom model one step further. Schrödinger used mathematical equations to describe the likelihood of finding an electron in a certain position. This atomic model is known as the quantum mechanical model of the atom.
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Discovered Neutrons in Atoms.
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He developed new theories in quantum mechanics about the behavior of electrons which agreed with the results of previous experiments. Heisenberg is most famous for his "uncertainty principle", which explains the impossibility of knowing exactly where something is and how fast it is moving.
