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John Dalton was the person who started the Atomic Theory. He began his theory by using evaporated gases, which he guessed the weight/size of the atom affected. His new theory said all matter is made of particles, atoms are indestructible and cannot be altered, and that when elements react, their outcomes aren't always a whole number ratio, but are always fixed for the elements regardless of quantity. His theory held true until nuclear fusion came into existence.
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The various models of the Atom over about 150 years. Including Dalton, Thomson, Rutherford, Bohr, and the Quantum Theory.
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The Louisiana Purchase took place in 1803, buying Lousiana from France. It bought most of America, and parts of Albert and Saskatchewan.
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Oh Canada!
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J. J. Thomson, the man who edited Dalton's original model, made his Atomic Model based on electric charge in a vacuum cathode-ray tube. He said that, because the rays were being deflected by magnets, that there must be "bodies much smaller than atoms," the electron. At this time he developed the new Atomic Model, including planetary, negative electrons orbiting a positive core. (The protons) He used the way light scattered to estimate the number of electrons in an atom.
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Rutherford studied under Thomson for some years, and eventually decided to take his model and improve it. His first experiment was to test whether an atom was mostly empty space or not. To test it, he shot alpha-ray particles at a piece of gold foil to see how the rays scatter. He proved that the atom has a very large nucleus in comparison to the electrons, and that the nucleus was a majority of the mass of the atom.
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Neils Bohr was the successor of Rutherford, who he studied under, and continued to build on it. He hypothesized that, because electrons can't be charged continuously, that when charged, they always move in an orbit around the nucleus. He heated an atom to test how the electrons reacted and proposed that electrons rotate in orbit, and the more chargered it is, the higher orbit it is in, up to three orbits. He added orbits and eletron shells to Rutherford's model, because of his test results.
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Over 9 million people died.
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The First World War ended.
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50 to 70 million died.
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The structure of DNA is found by James Watson and Francis Crick.
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Sputnik, the first successful satellite to lauch from Earth into Earth's orbit.
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The Quantum Model is a model cosisting of the work from J.J. Thomson, Max Planck, Neils Bohr, and Albert Einstein. Combining all of their models, and comparing them to new information, scientists put together, so far, the most accurate model for the atom. It says that there are more than three orbits, and that electrons are infinitely smaller that the nucleus.
