Timeline: The Discovery Of Elements

Early history The elements carbon, sulfur, iron, tin, lead, copper, mercury, silver, and gold are known to humans.
  Pre-a.d. 1600: The elements arsenic, antimony, bismuth, and zinc are known to humans.
1669 German physician Hennig Brand discovers phosphorus.
1735 Swedish chemist Georg Brandt discovers cobalt.
c. 1748 Spanish military Leader Don Antonio de Ulloa discovers platinum.
1751 Swedish mineralogist Axel Fredrik Cronstedt discovers nickel.
1766 English chemist and physicist Henry Cavendish discovers hydrogen.
1772 Scottish physician and chemist Daniel Rutherford discovers nitrogen.
1774 Swedish chemist Carl Wilhelm Scheele discovers chlorine.
1774 Swedish mineralogist Johann Gottlieb Gahn discovers manganese.
1774 English chemist Joseph Priestley and Swedish chemist Carl Wilhelm Scheele discover oxygen.
1781 Swedish chemist Peter Jacob Hjelm discovers molybdenum.
c. 1782 Austrian mineralogist Baron Franz Joseph Müller von Reichenstein discovers tellurium.
1783 Spanish scientists Don Fausto D'Elhuyard and Don Juan José D'Elhuyard, and Swedish chemist Carl Wilhelm Scheele discover tungsten.
1789 German chemist Martin Klaproth discovers uranium.
1789 German chemist Martin Klaproth discovers zirconium.
1791 English clergyman William Gregor discovers titanium.
1794 Finnish chemist Johan Gadolin discovers yttrium.
1797 French chemist Louis-Nicolas Vauquelin discovers chromium.
1798 French chemist Louis-Nicolas Vauquelin discovers beryllium.
1801 English chemist Charles Hatchett discovers niobium.
1801 Spanish-Mexican metallurgist Andrés Manuel del Río discovers vanadium.
1802 Swedish chemist and mineralogist Anders Gustaf Ekeberg discovers tantalum.
1803 English chemist and physicist William Hyde Wollaston discovers palladium.
1803 Swedish chemists Jöns Jakob Berzelius and Wilhelm Hisinger, and German chemist Martin Klaproth discover black rock of Bastnas, Sweden, which led to the discovery of several elements.
1804 English chemist and physicist William Hyde Wollaston discovers rhodium.
1804 English chemist Smithson Tennant discovers osmium.
1804 English chemist Smithson Tennant discovers iridium.
1807 English chemist Sir Humphry Davy discovers potassium.
1807 English chemist Sir Humphry Davy discovers sodium.
1808 English chemist Sir Humphry Davy discovers barium.
1808 English chemist Sir Humphry Davy discovers strontium.
1808 English chemist Sir Humphry Davy discovers calcium.
1808 English chemist Sir Humphry Davy discovers magnesium.
1808 French chemists Louis Jacques Thênard and Joseph Louis Gay-Lussac discover boron.
1811 French chemist Bernard Courtois discovers iodine.
1817 Swedish chemist Johan August Arfwedson discovers lithium.
1817 German chemist Friedrich Stromeyer discovers cadmium.
1818 Swedish chemists Jöns Jakob Berzelius and J. G. Gahn discover selenium.
1823 Swedish chemist Jöns Jakob Berzelius discovers silicon.
1825 Danish chemist and physicist Hans Christian Oersted discovers aluminum.
1826 French chemist Antoine-Jérôme Balard discovers bromine.
1828 Swedish chemist Jöns Jakob Berzelius discovers thorium.
1830 Swedish chemist Nils Gabriel Sefström rediscovers vanadium.
1839 Swedish chemist Carl Gustav Mosander discovers cerium.
1839 Swedish chemist Carl Gustav Mosander discovers lanthanum.
1843 Swedish chemist Carl Gustav Mosander discovers terbium.
1843 Swedish chemist Carl Gustav Mosander discovers erbium.
1844 Russian chemist Carl Ernst Claus discovers ruthenium.
c. 1861 German chemists Robert Bunsen and Gustav Kirchhoff discovers cesium.
c. 1861 German chemists Robert Bunsen and Gustav Kirchhoff discovers rubidium.
1861 British physicist Sir William Crookes discovers thallium.
1863 German chemists Ferdinand Reich and Hieronymus Theodor Richter discovers indium.
1875 Paul-émile Lecoq de Boisbaudran discovers gallium.
1878 Jean-Charles-Galissard de Marignac receives partial credit for the discovery of ytterbium.
1879 Swedish chemist Per Teodor Cleve discovers holmium.
1879 Swedish chemist Per Teodor Cleve discovers thulium.
1879 Swedish chemist Lars Nilson discovers scandium.
1879 Swedish chemist Lars Nilson receives partial credit for the discovery of ytterbium.
1880 French chemist Paul-Émile Lecoq de Boisbaudran discovers samarium.
1880 French chemist Jean-Charles-Galissard de Marignac discovers gadolinium.
1885 Austrian chemist Carl Auer (Baron von Welsbach) discovers praseodymium.
1885 Austrian chemist Carl Auer (Baron von Welsbach) discovers neodymium.
1885 German chemist Clemens Alexander Winkler discovers germanium.
1886 French chemist Henri Moissan discovers fluorine.
1886 French chemist Paul-Émile Lecoq de Boisbaudran discovers dysprosium.
1894 English chemists Lord Rayleigh and William Ramsav discover argon.
1895 English chemist Sir William Ramsay and Swedish chemists Per Teodor Cleve and Nils Abraham Langlet discover helium.
1898 English chemists William Ramsay and Morris Travers discover krypton.
1898 English chemists William Ramsay and Morris Travers discover neon.
1898 English chemists William Ramsay and Morris Travers discover xenon.
1898 French physicists Marie and Pierre Curie discover polonium.
1898 French physicists Marie and Pierre Curie discover radium.
1899 French chemist André Debierne discovers actinium.
1900 German physicist Friedrich Ernst Dorn discovers radon.
1901 French chemist Eugène-Anatole Demarçay discovers europium.
1907 French chemist Georges Urbain discovers lutetium.
1907 French chemist Georges Urbain receives partial credit for the discovery of ytterbium.
1917 German physicists Use Meitner and Otto Hahn discover protactinium.
1923 Dutch physicist Dirk Coster and Hungarian chemist George Charles de Hevesy discover hafnium.
1925 German chemists Walter Noddack, Ida Tacke, and Otto Berg discover rhenium.
1933 French chemist Marguerite Perey discovers francium.
1939 Italian physicist Emilio Segré and his colleague Carlo Perrier discover technetium.
1940 Edwin M. McMillan (1907-91) and Philip H. Abelson prepare neptunium.
1940 Dale R. Corson, Kenneth R. Mackenzie, and Emilio Segré discover astatine.
1940 University of California at Berkeley researcher Glenn Seaborg and others prepare plutonium.
1944 University of California at Berkeley researchers Glenn Seaborg, Albert Ghiorso, Ralph A. James, and Leon O. Morgan prepare americium.
1944 University of California at Berkeley researchers Glenn Seaborg, Albert Ghiorso, and Ralph A. James prepare curium.
1945 Scientists at the Oak Ridge Laboratory in Oak Ridge, Tennessee, discover promethium.
1949 University of California at Berkeley researchers prepare berkelium.
1950 University of California at Berkeley researchers Glenn Seaborg, Albert Ghiorso, Kenneth Street, Jr., and Stanley G. Thompson prepare californium.
1954 University of California at Berkeley researchers prepare einsteinium.
1954 University of California at Berkeley researcher Albert Ghiorso and others prepare fermium.
1960s & 1970s Researchers at the Joint Institute of Nuclear Research, in Dubna, Russia; the Lawrence Berkeley Laboratory at the University of California at Berkeley; and the Institute for Heavy Ion Research in Darmstadt, Germany, continue to prepare new transfermium elements.