History of the Periodic Table By cirini11092000 Jan 1, 1669 Hennig Brand Discovers Phosphorus (15) Jan 1, 1766 Henry Cavendish Discovers Hydrogen (1) Jan 1, 1772 Daniel Rutherford Discovers Nitrogen (7) Jan 1, 1774 Carl Wilhelm Scheele & Joseph Priestly isolate Oxygen (8) Jan 1, 1807 Sir Humphry Davy Discovers Sodium (11) Jan 1, 1809 About 47 Elements have been discovered Jan 1, 1869 Dmitri Mendeleev creates the first 'Periodic Table' Jan 1, 1886 Henri Moissan isolates Fluorine (9) Jan 1, 1894 Sir William Ramsay & Lord Rayleigh discover the noble gasses Jan 1, 1897 J.J Thomson discovers the electron Jan 1, 1898 Sir William Ramsay discovers Neon (10) Jan 1, 1914 Ernest Rutherford identifies protons as positively charged Jan 1, 1914 Henry Moseley gave the elements their atomic numbers Jan 1, 1932 James Chadwick discovers Neutrons and Isotopes Jan 1, 2003 Joint Institute for Nuclear Research creates Ununpentium (115) Jan 1, 2009 Flerov Laboratory of Nuclear Reactions create Ununseptium (117) May 10, 2016 4 New Elements Added to the Periodic Table (113, 115, 117 & 118)
