Timeline of Elements?

*500 BC- 1720: Alchemists used Ancient Art, during the middle Ages, to discover a substance that would change common metals to gold or silver. *442 BC: Democritus came up with the theory of atoms, and also he stated that the universe is made up of empty space and that all matter is composed of indivisible atoms. *384 - 322 BC: Aristotle developed techniques for gathering scientific facts. His progress provided the basis for scientific work more than a millennium. *1777: Lavoisier, …

…Uranium is bombarded by neutrons it produces smaller nuclei roughly half the size of the original Uranium nucleus. *1938- Lise Meitner realized that Hahn was splitting the Uranium nucleus, something never done before. *1951- Glen Seaborg succeeded in making man-made elements first. *1964- Murray Gell-Mann and George Zweig recommended the idea of quarks called up, down, or strange, unruffled of mesons and baryons, with spin 0.5 and electric charges of 2/3, -1/3, and -1/3 in that order.