Given is each element's name, atomic number, year of first report, name of the discoverer, and some notes related to the discovery.
| Z | Name | Earliest use | Oldest remaining sample | Discoverers | Place of oldest sample | Notes |
|---|---|---|---|---|---|---|
| 29 | Copper | 9000 BCE | 6000 BCE | Middle East | Anatolia | Copper was probably the first metal mined and crafted by man. Earliest estimates of discovery of copper suggest around 9000 BCE in the Middle East. It is one of the most important materials to humans throughout the entire copper and bronze ages. Copper beads dating from 6000 BCE were found in Çatal Höyük, Anatolia. |
| 79 | Gold | before 6000 BCE | 5500 BCE | Middle East | Egypt | Archaeologists suggest that first use of gold began with the first civilizations in the Middle East. It may have been the first metal used by humans. Oldest remaining gold jewelry is that in the tomb of Egyptian Queen Zer. |
| 82 | Lead | 7000 BCE | 3800 BCE | Near East | Abydos | It is believed that lead smelting began at least 9000 years ago, and the oldest known artifact of lead is statuette found at the temple of Osiris on the site of Abydos dated circa 3800 BC. Lead was first purified and clearly differentiated from tin by medieval Arabic chemists |
| 47 | Silver | before 5000 BCE | ~4000 BCE | Asia Minor | ? | Estimated to have happened to shortly after that of copper and gold. |
| 26 | Iron | before 5000 BCE | 4000BCE | ? | Egypt | There is evidence that iron is known from before 5000 BCE. The oldest known iron objects used by humans are some beads made from meteorite iron, in Egypt, made about 4000BCE. Discovery of smelting around 3000 BCE lead to the prominence of use of iron for tools and weapons, which lead to the start of iron age around 1200 BCE. |
| 6 | Carbon | 3750 BCE | ? | Egyptians and Sumerians | ? | Earliest known use of charcoal for the reduction of copper, zinc and tin ores in the manufacture of bronze, by the Egyptians and Sumerians. Diamonds were probably known as early as 2500 BCE First true chemical analyses were made in the 18th century CE, and in 1789 was listed by Antoine Lavoisier as an element. |
| 50 | Tin | 3500 BCE | 2000 BCE | ? | ? | First smelt in combination with copper around 3500 BCE to produce bronze and brass. Oldest artifacts date around 200 BCE. First purified and clearly differentiated from lead by medieval Arabic chemists (ca. 700–1400 CE). |
| 16 | Sulfur | before 2000 BCE | ? | Chinese/Indians | ? | First used at least 4000 years ago. First identified as an element by Geber (ca. 800 CE). Also recognized as an element by Antoine Lavoisier in 1777. |
| 80 | Mercury | before 2000 BCE | 1500 BCE | Chinese/Indians | Egypt | Known to ancient Chinese and Hindus before 2000 BC, and found in Egyptian tombs dating from 1500 BCE. First identified as an element by Geber (ca. 800 CE). |
| 30 | Zinc | before 1000 BCE | 1000 BCE | Indian metallurgists | Indian subcontinent | Extracted as a metal since antiquity by Indian metallurgists before 1000 BCE, but the true nature of this metal was not understood in ancient times. Identified as a unique metal by the metallurgist Rasaratna Samuccaya in 800 CE and by the alchemist Paracelsus in 1526. Isolated by Andreas Sigismund Marggraf in 1746. |
| Z | Element name | Observed or predicted | Report of characterization (widely recognized) | Isolation (widely known) | Observer | Person who widely reported first characterization (usually accepted discoverer) | First isolator | Notes |
|---|---|---|---|---|---|---|---|---|
| 33 | Arsenic | 800 CE (ca.) | ? | 800 CE (ca.) | Geber | Geber or A.Magnus | Geber | Discovered and isolated by Geber, who described its preparation in his Liber Fornacum, ca. 800 CE. Albertus Magnus was the first European to isolate the element in 1250. In 1649, Johann Schröder published two ways of preparing elemental arsenic. |
| 51 | Antimony | 800 (ca.) | 800 (ca.) | Geber | Geber | Discovered and isolated by Geber ca. 800 CE. Basilius Valentinus was the first European to describe the element around 1450. First description of a procedure for isolating elemental antimony in 1540 by Vannoccio Biringuccio. | ||
| 83 | Bismuth | 800 (ca.) | 1753 | Geber | C.F.Geoffroy | Discovered by Geber ca. 800. Later described in writings attributed to Basilius Valentinus around 1450. Definitively identified by Claude François Geoffroy in 1753. | ||
| 15 | Phosphorus | 1669 | 1669 | H.Brand | H.Brand | Prepared from urine, it was the first element to be chemically discovered. | ||
| 27 | Cobalt | 1732 | ? | G.Brandt | ? | Proved that the blue color of glass is due to a new kind of metal and not bismuth as thought previously. | ||
| 78 | Platinum | 1735 | 1735 | A.de Ulloa | A. de Ulloa | First description of a metal found in South American gold was in 1557 by Julius Caesar Scaliger. Ulloa published his findings in 1748, but Sir Charles Wood also investigated the metal in 1741. First reference to it as a new metal was made by William Brownrigg in 1750. | ||
| 28 | Nickel | 1751 | 1751 | A.F.Cronstedt | A.F.Cronstedt | By attempting to extract copper from the mineral known as "fake copper" (now known as niccolite). | ||
| 12 | Magnesium | 1755 | 1808 | J.Black | H.Davy | Black observed that magnesia alba (MgO) was not quicklime (CaO). Davy isolated it electrochemically from magnesia. | ||
| 1 | Hydrogen | 1766 | 1500(ca.) | H.Cavendish | Paracelsus | Cavendish was the first to distinguish from other gases, although Paracelsus around 1500, Robert Boyle, and Joseph Priestley had observed its production by reacting strong acids with metals. Lavoisier named it in 1793. | ||
| 8 | Oxygen | 1771 | 1771 | C.W.Scheele | C.W.Scheele | Obtained from by heating mercuric oxide and nitrates in 1771, but published his findings in 1777. Joseph Priestley also prepared this new air by 1774, but only Lavoisier recognized it as a true element and named it in 1777. | ||
| 7 | Nitrogen | 1772 | 1772 | D.Rutherford | D.Rutherford | He showed that the air in which animals had breathed, even after removal of the exhaled carbon dioxide, was no longer able to burn a candle. Carl Wilhelm Scheele, Henry Cavendish, and Joseph Priestley also studied the element about the same time, and Lavoisier named it in 1775-6. | ||
| 17 | Chlorine | 1774 | 1774 | C.W.Scheele | C.W.Scheele | Obtained it from hydrochloric acid, but thought it was an oxide. Only in 1808 Humphry Davy recognized it as an element. | ||
| 25 | Manganese | 1770 | 1774 | T.O.Bergman | J.G.Gahn | Distinguished pyrolusite as the calx of a new metal. Ignatius Gottfred Kaim also discovered the new metal in 1770 and Scheele in 1774 too. It was isolated by reduction of manganese dioxide with carbon. | ||
| 56 | Barium | 1772 | 1808 | C.W.Scheele | H.Davy | Scheele distinguished a new earth (BaO) in pyrolusite and Davy isolated the metal by elecrolysis. | ||
| 42 | Molybdenum | 1778 | 1781 | C.W.Scheele | P.J.Hjelm | Scheele recognised as a constituent of molybdena. | ||
| 52 | Tellurium | 1782 | 1795? | F.-J.M. von Reichenstein | M.H.Klaproth | Muller observed it as an impurity in gold ores from Transylvania. | ||
| 74 | Tungsten | 1781 | 1783 | T.Bergman | J.J.Elhuyar, J.José &F.Elhuyar | Bergman obtained from scheelite an oxide of a new element. The Elhuyars obtained tungstic acid from wolframite and reduced it with charcoal. | ||
| 38 | Strontium | 1787 | 1808 | W.Cruikshank | H.Davy | Cruikshank and Adair Crawford in 1790 concluded that strontianite contained a new earth. It was eventually isolated electrochemically in 1808 by Humphry Davy. | ||
| 1789 | A.Lavoisier | The first modern list of chemical elements, containing among others, 23 elements of those known then. He also redefined the term "element". Until him, all metals except mercury were not considered elements. | ||||||
| 40 | Zirconium | 1789 | 1824 | M.H.Klaproth | J.J.Berzelius | Klaproth identified the a new element in zirconia. | ||
| 92 | Uranium | 1789 | 1841 | M.H.Klaproth | E.-M.Péligot | Mistakenly identified an uranium oxide obtained from pitchblende as the element itself and named it after the recently discovered planet Uranus. | ||
| 22 | Titanium | 1791 | 1825 | W.Gregor | J.J.Berzelius | Gregor found an oxide of a new metal in ilmenite and Martin Heinrich Klaproth independently discovered the element in rutile in 1795 and named it. Pure metallic form was obtained only in 1910 by Matthew A. Hunter. | ||
| 39 | Yttrium | 1794 | 1840 | J.Gadolin | C.G.Mosander | Discovered in gadolinite, but Mosander showed later that it contained more elements. | ||
| 24 | Chromium | 1797 | 1798 | L.N.Vauquelin | L.N.Vauquelin | Discovered and isolated from crocoite. | ||
| 4 | Beryllium | 1798 | 1828 | L.N.Vauquelin | F.Wöhler&A.Bussy | Vauquelin discovered the oxide in beryl and emerald, and Klaproth suggested the present name around 1808. | ||
| 23 | Vanadium | 1801 | 1830 | A.M.del Río | N.G.Sefström | Río found the metal in vanadinite but retracted the claim after Hippolyte Victor Collet-Descotils disputed it. Sefström isolated and named it, and later it was shown that Río had been right in the first place. | ||
| 41 | Niobium | 1801 | 1864 | C.Hatchett | C.W.Blomstrand | Hatchett found the element in columbite ore and named it columbium. Heinrich Rose proved in 1844 that the element is distinct from tantalum, and renamed it niobium which was officially accepted in 1949. | ||
| 73 | Tantalum | 1802 | ? | A.G.Ekeberg | ? | Ekeberg found another element in minerals similar to columbite and in 1844, Heinrich Rose proved that it was distinct from niobium. | ||
| 46 | Palladium | 1802 | 1802 | W.H.Wollaston | W.H.Wollaston | Wollaston discovered it in samples of platinum from South America, but did not publish his results immediately. He had intended to name it after the newly discovered asteroid, Ceres, but by the time he published his results in 1804, cerium had taken that name. Wollaston named it after the more recently discovered asteroid Pallas. | ||
| 58 | Cerium | 1803 | 1839 | M.H.Klaproth, J.J.Berzelius & W.Hisinger | C.G.Mosander | Berzelius and Hisinger discovered the element in ceria and named it after the newly discovered asteroid (then considered a planet), Ceres. Klaproth discovered it simultaneously and independently in some tantalum samples. Mosander proved later that the samples of all three researchers had at least another element in it, lanthanum. | ||
| 76 | Osmium | 1803 | 1803 | S.Tennant | S.Tennant | Tennant had been working on samples of South American platinum in parallel with Wollaston and discovered two new elements, which he named osmium and iridium. | ||
| 77 | Iridium | 1803 | 1803 | S.Tennant | S.Tennant | Tennant had been working on samples of South American platinum in parallel with Wollaston and discovered two new elements, which he named osmium and iridium, and published the iridium results in 1804. | ||
| 45 | Rhodium | 1804 | 1804 | W.H.Wollaston | W.H.Wollaston | Wollaston discovered and isolated it from crude platinum samples from South America. | ||
| 19 | Potassium | 1807 | 1807 | H.Davy | H.Davy | Davy discovered it by using electrolysis on potash. | ||
| 11 | Sodium | 1807 | 1807 | H.Davy | H.Davy | Davy discovered it a few days after potassium, by using electrolysis on soda. | ||
| 20 | Calcium | 1808 | 1808 | H.Davy | H.Davy | Davy discovered the metal by electrolysis of quicklime. | ||
| 5 | Boron | 1808 | 1808 | J.L.Gay-Lussac & L.J.Thénard | H.Davy | On June 30, 1808, Lussac and Thénard announced a new element in sedative salt, and nine days later Davy announced the isolation of metallic boron. | ||
| 53 | Iodine | 1811 | 1811 | B.Courtois | B.Courtois | Courtois discovered it in the ashes of sea weed. | ||
| 3 | Lithium | 1817 | 1817 | J.A.Arfwedson | J.A.Arfwedson | Arfwedson discovered the alkali in petalite. | ||
| 48 | Cadmium | 1817 | 1817 | K.S.L Hermann, F.Stromeyer& J.C.H. Roloff | K.S.L Hermann, F. Stromeyer, J.C.H. Roloff | All three found an unknown metal in a sample of zinc oxide from Silesia, but the name that Stromeyer gave became the accepted one. | ||
| 34 | Selenium | 1817 | 1817 | J.J.Berzelius & J.G.Gahn | J.J.Berzelius & J.G.Gahn | While working with lead they discovered a substance that they thought it is tellurium, and after realizing it is different. | ||
| 14 | Silicon | 1824 | 1824 | J.J.Berzelius | J.J.Berzelius | Humphry Davy thought in 1800 that silica is an element, not a compound, and in 1808 suggested the present name. In 1811 Louis-Joseph Gay-Lussac and Louis-Jacques Thénard probably prepared impure silicon, but Berzelius is credited with the discovery for obtaining the pure element in 1824. | ||
| 13 | Aluminium | 1825 | 1825 | H.C.Ørsted | H.C.Ørsted | Antoine Lavoisier predicted in 1787 that alumine is the oxide of an undiscovered element, and in 1808 Humphry Davy tried to decompose it, and although failed, suggested the present name. Hans Christian Ørsted was the first to isolate metallic aluminum in 1825. | ||
| 35 | Bromine | 1825 | 1825 | A.J.Balard, L.Gmelin | A.J.Balard & L.Gmelin | They both discovered the element in the Autumn of 1825, and published the results next year. | ||
| 90 | Thorium | 1829 | ? | J.J.Berzelius | ? | Berzelius obtained the oxide of a new earth in thorite. | ||
| 57 | Lanthanum | 1838 | ? | C.G.Mosander | ? | Mosander found a new element in samples of ceria and published his results in 1842, but later, he showed that this lanthana contained four more elements. | ||
| 68 | Erbium | 1842 | ? | C.G.Mosander | ? | Mosander managed to split the old yttria into yttria proper and erbia, and later terbia too. | ||
| 65 | Terbium | 1842 | 1842 | C.G.Mosander | C.G.Mosander | In 1842 Mosander split yttria into two more earths, erbia and terbia | ||
| 44 | Ruthenium | 1807 | 1807 | J.Sniadecki | J.Sniadecki | Sniadecki isolated the element in 1807 but his work was not ratified. Gottfried Wilhelm Osann thought thought he found three new metals in Russian platinum samples, and in 1844, Karl Karlovich Klaus confirmed that there was a new element. The latter is usually recognized as the discoverer of the element. | ||
| 55 | Caesium | 1860 | 1882 | R.W.Bunsen & G.R.Kirchhoff | C.Setterberg | Bunsen and Kirchhoff were the first to suggest finding new elements by spectrum analysis. They discovered caesium by its two blue emission lines in a sample of Dürkheim mineral water. The pure metal was eventually isolated in 1962 by Setterberg. | ||
| 37 | Rubidium | 1861 | ? | R.W.Bunsen & G.R.Kirchhoff | Hevesy | Bunsen and Kirchhoff discovered it just a few months after caesium, by observing new spectral lines in the mineral lepidolite. Bunsen never obtained a pure sample of the metal, which was later obtained by Hervesy. | ||
| 81 | Thallium | 1861 | 1862 | W.Crookes | C.-A.Lamy | Shortly after the discovery of rubidium, Crookes found a new green line in a selenium sample and later that year, Lamy found the element to be metallic. | ||
| 49 | Indium | 1863 | 1867 | F.Reich & H.T.Richter | T.Richter | Riach and Richter First identified it in sphalerite by its birght indigo-blue spectroscopic emission line. Richter isolated the metal several years later. | ||
| 2 | Helium | 1868 | 1895 | P.Janssen & J.N.Lockyer | W.Ramsay, P.T.Cleve& N.Langlet | Janssen and Lockyer observed independently a yellow spectral line in the solar spectrum that did not match any other element. Years later, Ramsay, Cleve, and Langlet observed independently the element trapped in clevite about the same time. | ||
| 1869 | Mendeleev arranges the 66 elements known at that time into the first modern periodic table and correctly predicts several others. | |||||||
| 31 | Gallium | 1875 | ? | P.E.L.de Boisbaudran | P.E.L.de Boisbaudran | Boisbaudran observed on a Pyrenea blende sample some emission lines corresponding to the eka-aluminum that was predicted by Mendeleev in 1871 and subsequently isolated the element by electrolysis. | ||
| 70 | Ytterbium | 1878 | ? | J.C.G. de Marignac | ? | In October 22, 1878, Marignac reported splitting terbia in two new earths, terbia proper and ytterbia. | ||
| 67 | Holmium | 1878 | ? | M.Delafontaine | ? | Delafontaine found it in samarskite and next year, Per Teodor Cleve split Marignac's erbia into erbia proper and two new elements, thulium and holmium. | ||
| 69 | Thulium | 1879 | 1879 | P.T.Cleve | P.T.Cleve | Cleve split Marignac's erbia into erbia proper and two new elements, thulium and holmium. | ||
| 21 | Scandium | 1879 | 1879 | L.F.Nilson | L.F.Nilson | Nilson split Marignac's ytterbia into pure one and a new element that matched 1871 Mendeleev's predicted eka-boron. | ||
| 62 | Samarium | 1879 | 1879 | P.E.L. de Boisbaudran | P.E.L. de Boisbaudran | Boisbaudran noted a new earth in samarskite and named it after the mineral. | ||
| 64 | Gadolinium | 1880 | 1886 | J.C.G. de Marignac | F.L. de Boisbaudran | Marignac initially observed the new earth in terbia and later, Boisbaudran obtained a pure sample from samarskite. | ||
| 59 | Praseodymium | 1885 | ? | C.A.von Welsbach | ? | Von Welsbach discovered two new distinct elements in ceria: praseodymium and neodymium. | ||
| 60 | Neodymium | 1885 | ? | C.A.von Welsbach | ? | Von Welsbach discovered two new distinct elements in ceria: praseodymium and neodymium. | ||
| 66 | Dysprosium | 1886 | ? | P.E.L. de Boisbaudran | ? | De Boisbaudran found a new earth in erbia. | ||
| 32 | Germanium | 1886 | ? | C.A.Winkler | ? | In February 1886 Winkler found in argyrodite the eka-silicon that Mendeleev had predicted in 1871. | ||
| 9 | Fluorine | 1886 | 1886 | H.Moissan | H.Moissan | Lavoisier predicted an element obtained from hydrofluoric acid and between 1812 and 1886 many researchers tried to obtain this element. It was eventually isolated by Moissan. | ||
| 18 | Argon | 1894 | 1894 | Lord Rayleigh & W.Ramsay | Lord Rayleigh & W.Ramsay | They discovered the gas by comparing the molecular weights of nitrogen prepared by liquefaction from air and nitrogen prepared by chemical means. It is the first noble gas to be isolated. | ||
| 36 | Krypton | 1898 | 1898 | W.Ramsay & M.W.Travers | W.Ramsay & M.W.Travers | On May 30, 1898, Ramsay separated a third noble gas from liquid argon by difference in boiling point. | ||
| 10 | Neon | 1898 | 1898 | W.Ramsay & M.W.Travers | W.Ramsay & M.W.Travers | In June 1898 Ramsay separated a new noble gas from liquid argon by difference in boiling point. | ||
| 54 | Xenon | 1898 | 1898 | W.Ramsay & M.W.Travers | W.Ramsay & M.W.Travers | On July 12, 1898 Ramsay separated a third noble gas within three weeks, from liquid argon by difference in boiling point. | ||
| 84 | Polonium | 1898 | 1902 | P.Curie & M.Curie | W.Marckwald | In an experiment done on July 13, 1898, the Curies noted an increased radioactivity in the uranium obtained from pitchblende which they assigned to an unknown element. | ||
| 88 | Radium | 1898 | 1902 | P.Curie & M.Curie | M. Curie | The Curies reported on December 26, 1898, a new element different from polonium, which Marie later isolated from uraninite. | ||
| 86 | Radon | 1898 | 1910 | F.E.Dorn | W.Ramsay & R.Whytlaw-Gray | Dorn discovered a radioactive gas resulting from the radioactive decay of radium, isolated later by Ramsay and Gray. | ||
| 89 | Actinium | 1899 | 1899 | A.-L.Debierne | A.-L.Debierne | Debierne obtained from pitchblende a substance that had similar properties to thorium. | ||
| 63 | Europium | 1896 | 1901 | E.Demarcay | E.Demarcay | Demarçay found spectral lines of a new element in Lecoq's samarium, and separated this element several years later. | ||
| 71 | Lutetium | 1906 | 1906 | G.Urbain, C.A. von Welsbach | G. Urbain & C.A. von Welsbach | Urbain and von Welsbach proved independently that the old ytterbium did also contain a new element. | ||
| 75 | Rhenium | 1908 | 1908 | M.Ogawa | M.Ogawa | Ogawa found it in thorianite but assigned it is element 43 instead of 75 and named it nipponium. In 1922 Walter Noddack, Ida Eva Tacke and Otto Berg announced its separation from gadolinite and gave it the present name. | ||
| 72 | Hafnium | 1911 | 1922 | G.Urbain, V.I.Vernadskij | D.Coster & G. von Hevesy | Urbain claimed to have found the element in rare-earth residues, while Vernadskij independently found it in orthite. Neither clamis were confirmed due to the War. After it, Coster and Hevesy found it by X-ray spectroscopic analysis in Norwegian zircon. It is the last stable element to be discovered. | ||
| 91 | Protactinium | 1913 | ? | O.H.Göhring, K.Fajans | ? | The two obtained the first isotope of this element that had been predicted by Mendeleev in 1871 as a member of the natural decay of 238U. Originally isolated in 1900 by William Crookes. | ||
| 43 | Technetium | 1937 | 1937 | C.Perrier, E.Segrè | C.Perrier & E.Segrè | The two discovered a new element in a molybdenum that was used in a cyclotrone, the first synthetic element to be discovered. It had been predicted by Mendeleev in 1871 as eka-manganese. | ||
| 87 | Francium | 1939 | 1939 | M.Perey | M.Perey | Perey discovered it as a decay product of 227Ac. Francium is the last element to be discovered in nature, rather than synthesized in the lab, although some of the "synthetic" elements that were discovered later (plutonium, neptunium, astatine) were eventually found in trace amounts in nature as well. | ||
| 85 | Astatine | 1940 | ? | D.R.Corson, K.R.Mackenzie, E.Segrè | ? | Obtained by bombarding bismuth with alpha particles. Later determined to occur naturally in minuscule quantitites (<25 grams in earth's crust). | ||
| 93 | Neptunium | 1940 | ? | E.M. McMillan, P.H.Abelson | ? | Obtained by irradiating uranium with neutrons, it is the first transuranium element discovered. | ||
| 94 | Plutonium | 1940-1 | ? | G.T.Seaborg, Arthur C. Wahl, J.K.Kennedy, E.M.McMillan | ? | Prepared by bombardment of uranium with deuterons. | ||
| 95 | Americium | 1944 | ? | G.T.Seaborg, R.A.James, L.O.Morgan & A.Ghiorso | ? | Prepared by irradiating plutonium with neutrons during the Manhattan Project. | ||
| 96 | Curium | 1944 | ? | G.T.Seaborg, R.A.James, A.Ghiorso | ? | Prepared by bombarding plutonium with alpha particles during the Manhattan Project | ||
| 61 | Promethium | 1942 | 1945 | C.S.Wu, E.G.Segrè, H.A.Bethe | Charles D. Coryell, Jacob A. Marinsky, Lawrence E. Glendenin, Harold G. Richter | It was probably first prepared in 1942 by bombarding neodymium and praseodymium with neutrons, but separation of the element could not be carried out. Isolation was performed under the Manhattan Project in 1945. | ||
| 97 | Berkelium | 1949 | ? | S.G.Thompson, A.Ghiorso, G.T.Seaborg | ? | Created by bombardment of americium with alpha particles. | ||
| 98 | Californium | 1950 | ? | S.G.Thompson, K.Street,Jr., A.Ghiorso, G.T.Seaborg | ? | Bombardment of curium with alpha particles. | ||
| 99 | Einsteinium | 1952 | 1952 | A.Ghiorso et. al (Argonne Laboratory, Los Alamos Laboratory, and University of California) | Formed in the first thermonuclear explosion in November 1952, by irradiation of uranium with neutronsand kept secret for several years. | |||
| 100 | Fermium | 1952 | ? | A.Ghiorso et. al (Argonne Laboratory, Los Alamos Laboratory, and University of California) | Formed in the first thermonuclear explosion in November 1952, by irradiation of uranium with neutrons and kept secret for several years. | |||
| 101 | Mendelevium | 1955 | ? | A.Ghiorso, B.G.Harvey, G.R.Choppin, S.G.Thompson, G.T.Seaborg | ? | Prepared by bombardment of einsteinium with helium. | ||
| 102 | Nobelium | 1958 | ? | A.Ghiorso, T.Sikkeland, J.R.Walton, G.T.Seaborg | ? | First prepared by bombardment of curium with carbon atoms. | ||
| 103 | Lawrencium | 1961 | ? | A.Ghiorso, T.Sikkeland, A.E.Larsh, R.M.Latimer | ? | First prepared by bombardment of californium with boron atoms. | ||
| 104 | Rutherfordium | 1964 | ? | G.N.Flerov et. al at JINR in Dubna | ? | Prepared by bombardment of plutonium with neon atoms. | ||
| 105 | Dubnium | 1968 | ? | G.N.Flerov et. al at JINR in Dubna | ? | By bombardment of americium with neon atoms. | ||
| 106 | Seaborgium | 1974 | ? | A.Ghiorso et. al in University of California, Berkeley | ? | Collisions of californium-249 with oxygen atoms. | ||
| 107 | Bohrium | 1981 | ? | G.Münzenberg et. al GSI in Darmstadt | ? | Obtained by bombarding bismuth with chromium. | ||
| 109 | Meitnerium | 1982 | ? | G.Münzenberg, P.Armbruster et. al GSI in Darmstadt | ? | Bombardment of bismuth with iron atoms. | ||
| 108 | Hassium | 1984 | ? | G.Münzenberg, P.Armbruster et. al at GSI in Darmstadt | ? | Bombardment of lead with iron atoms | ||
| 110 | Darmstadtium | 1994 | ? | S.Hofmann et al at GSI in Darmstadt | ? | Bombardment of lead with nickel. | ||
| 111 | Roentgenium | 1994 | ? | S.Hofmann et al at GSI in Darmstadt | ? | Bombardment of bismuth with nickel. |
| Z | Name | Discovery year | Discoverer | Notes |
|---|---|---|---|---|
| 112 | Ununbium | 1996 | S. Hofmann, V. Ninov et al, GSI | |
| 114 | Ununquadium | 1999 | Joint Institute for Nuclear Research in Dubna | |
| 116 | Ununhexium | 2000 | Joint Institute for Nuclear Research in Dubna | |
| 118 | Ununoctium | 2002 | Joint Institute for Nuclear Research in Dubna and Lawrence Livermore National Laboratory | |
| 113 | Ununtrium | 2003 | Joint Institute for Nuclear Research in Dubna and Lawrence Livermore National Laboratory | |
| 115 | Ununpentium | 2003 | Joint Institute for Nuclear Research in Dubna and Lawrence Livermore National Laboratory | |
| 122 | Unbibium | 2008 | Hebrew University of Jerusalem | Disputed claim: A group led by Amnon Marinov at the Hebrew University of Jerusalem claims to have found single atoms of unbibium in naturally occurring thorium deposits at a concentration of between 10-11 and 10-12. If this is accurate, unbibium would be the first naturally occurring element to be discovered in nature since Francium. |