element

imeline of chemical elements discoveries

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The discovery of the elements known to exist today is presented here in chronological order. The elements are listed generally in the order in which each was first defined as the pure element, as the exact date of discovery of most elements cannot be accurately defined.
Given is each element's name, atomic number, year of first report, name of the discoverer, and some notes related to the discovery.

Contents [show] 1 Table 2 Unrecorded discoveries 3 Recorded discoveries 4 Recent discoveries 5 See also 6 References 7 External links

[edit] Table

Group #	1	2	3	4	5	6	7	8	9	10	11	12	13	14	15	16	17	18
Period
1	1 H																	2 He
2	3 Li	4 Be											5 B	6 C	7 N	8 O	9 F	10 Ne
3	11 Na	12 Mg											13 Al	14 Si	15 P	16 S	17 Cl	18 Ar
4	19 K	20 Ca	21 Sc	22 Ti	23 V	24 Cr	25 Mn	26 Fe	27 Co	28 Ni	29 Cu	30 Zn	31 Ga	32 Ge	33 As	34 Se	35 Br	36 Kr
5	37 Rb	38 Sr	39 Y	40 Zr	41 Nb	42 Mo	43 Tc	44 Ru	45 Rh	46 Pd	47 Ag	48 Cd	49 In	50 Sn	51 Sb	52 Te	53 I	54 Xe
6	55 Cs	56 Ba	*	72 Hf	73 Ta	74 W	75 Re	76 Os	77 Ir	78 Pt	79 Au	80 Hg	81 Tl	82 Pb	83 Bi	84 Po	85 At	86 Rn
7	87 Fr	88 Ra	**	104 Rf	105 Db	106 Sg	107 Bh	108 Hs	109 Mt	110 Ds	111 Rg	112 Cn	113 Uut	114 Uuq	115 Uup	116 Uuh	117 Uus	118 Uuo
* Lanthanoids			57 La	58 Ce	59 Pr	60 Nd	61 Pm	62 Sm	63 Eu	64 Gd	65 Tb	66 Dy	67 Ho	68 Er	69 Tm	70 Yb	71 Lu
** Actinoids			89 Ac	90 Th	91 Pa	92 U	93 Np	94 Pu	95 Am	96 Cm	97 Bk	98 Cf	99 Es	100 Fm	101 Md	102 No	103 Lr

Legend

• Before 1800 (34 elements): discoveries during and before the age of enlightenment.
• 1800-1849 (+24 elements): science and industrial revolutions.
• 1850-1899 (+26 elements): the age of classifying elements received the impulse of the spectrum analysis. Boisbaudran, Bunsen, Crookes, Kirchhoff, and others "hunting emission line signatures".
• 1900-1949 (+13 elements): impulse with the old quantum theory and quantum mechanics.
• 1950-1999 (+16 elements): "post atomic bomb" issues for atomic numbers 98 and above (colliders, bombardment techniques).
• 2000-present (+5 elements): very recent discoveries.

[edit] Unrecorded discoveries

Z	Name	Earliest use	Oldest remaining sample	Discoverers	Place of oldest sample	Notes
29	Copper	9000 BC	6000 BC	Middle East	Anatolia	Copper was probably the first metal mined and crafted by man.[1] Earliest estimates of discovery of copper suggest around 9000 BC 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 BC were found in Çatal Höyük, Anatolia.[2]
79	Gold	before 6000 BC	5500 BC	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[dubious – discuss].[3][4]
82	Lead	7000 BC	3800 BC	Near East	Abydos, Egypt	It is believed that lead smelting began at least 9000 years ago, and the oldest known artifact of lead is a statuette found at the temple of Osiris on the site of Abydos dated circa 3800 BC.[5]
47	Silver	before 5000 BC	~4000 BC	?	Asia Minor	Estimated to have occurred shortly after the discovery of copper and gold.[6][7]
26	Iron	before 5000 BC	4000 BC	?	Egypt	There is evidence that iron is known from before 5000 BC.[8] The oldest known iron objects used by humans are some beads made from meteorite iron, in Egypt, made about 4000 BC. Discovery of smelting around 3000 BC lead to the prominence of use of iron for tools and weapons, which lead to the start of the iron age around 1200 BC.[9]
6	Carbon	3750 BC	?	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 Samaritans.[10] Diamonds were probably known as early as 2500 BC[11] First true chemical analyses were made in the 18th century,[12] and in 1789 was listed by Antoine Lavoisier as an element.[13]
50	Tin	3500 BC	2000 BC	?	?	First smelt in combination with copper around 3500 BC to produce bronze and brass.[14] Oldest artifacts date around 2000 BC.[15]
16	Sulfur	before 2000 BC	?	Chinese/Indians	?	First used at least 4000 years ago.[16] Recognized as an element by Antoine Lavoisier in 1777.
80	Mercury	before 2000 BC	1500 BC	Chinese/Indians	Egypt	Known to ancient Chinese and Hindus before 2000 BC, and found in Egyptian tombs dating from 1500 BC.[17]
30	Zinc	before 1000 BC	1000 BC	Indian metallurgists	Indian subcontinent	Extracted as a metal since antiquity by Indian metallurgists before 1000 BC, 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 [18] and by the alchemist Paracelsus in 1526.[19] Isolated by Andreas Sigismund Marggraf in 1746.
33	Arsenic	2500 BC/1250 AD	bronze age	A.Magnus		In use in the early bronze age, Albertus Magnus was the first European to isolate the element in 1250.[20][21] In 1649, Johann Schröder published two ways of preparing elemental arsenic.
51	Antimony	3000 BC				Wide spread use in Egypt and the middle east Basilius Valentinus was the first European to describe the element around 1450.[20][21] First description of a procedure for isolating elemental antimony in 1540 by Vannoccio Biringuccio.
83	Bismuth	1753		C.F.Geoffroy		Described in writings attributed to Basilius Valentinus around 1450.[20] Definitively identified by Claude François Geoffroy in 1753.[21]

[edit] Recorded discoveries

Z	Element name	Observed or predicted	Report of characterization (widely recognized) [20][21]	Isolation (widely known)	Observer	First isolator	Notes
15	Phosphorus	1669		1669	H.Brand	H.Brand	Prepared from urine, it was the first element to be chemically discovered.[22]
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.[23]
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.[24]
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).[25]
12	Magnesium	1755		1808	J.Black	H.Davy	Black observed that magnesia alba (MgO) was not quicklime (CaO). Davy isolated it electrochemically from magnesia.[26]
1	Hydrogen	1766		1500	H.Cavendish	Paracelsus	Cavendish was the first to distinguish H2 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.[27][28]
8	Oxygen	1771		1771	C.W.Scheele	C.W.Scheele	Obtained 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.[29][30]
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.[31]
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.[32]
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.[33]
56	Barium	1772		1808	C.W.Scheele	H.Davy	Scheele distinguished a new earth (BaO) in pyrolusite and Davy isolated the metal by electrolysis.[34]
42	Molybdenum	1778		1781	C.W.Scheele	P.J.Hjelm	Scheele recognised as a constituent of molybdena.[35]
52	Tellurium	1782		1795?	F.-J.M. von Reichenstein	M.H.Klaproth	Muller observed it as an impurity in gold ores from Transylvania.[36]
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.[37]
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.[38]
		1789			A.Lavoisier		The first modern list of chemical elements, containing among others, 23 elements of those known then.[39] 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 a new element in zirconia.[40][41]
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.[42][43]
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.[44][45]
39	Yttrium	1794		1840	J.Gadolin	C.G.Mosander	Discovered in gadolinite, but Mosander showed later that it contained more elements.[46][47]
24	Chromium	1797		1798	L.N.Vauquelin	L.N.Vauquelin	Discovered and isolated from crocoite.[48]
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.[49]
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.[50]
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.[51]
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.[52]
46	Palladium	1803		1803	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.[53]
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.[54]
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.[55]
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.[56]
45	Rhodium	1804		1804	W.H.Wollaston	W.H.Wollaston	Wollaston discovered and isolated it from crude platinum samples from South America.[57]
19	Potassium	1807		1807	H.Davy	H.Davy	Davy discovered it by using electrolysis on potash.[58]
11	Sodium	1807		1807	H.Davy	H.Davy	Davy discovered it a few days after potassium, by using electrolysis on sodium hydroxide.[59]
20	Calcium	1808		1808	H.Davy	H.Davy	Davy discovered the metal by electrolysis of quicklime.[59]
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.[60]
53	Iodine	1811		1811	B.Courtois	B.Courtois	Courtois discovered it in the ashes of sea weed.[61]
3	Lithium	1817		1817	J.A.Arfwedson	J.A.Arfwedson	Arfwedson discovered the alkali in petalite.[62]
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.[63]
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.[64]
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.[65]
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.[66]
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.[67]
90	Thorium	1829		?	J.J.Berzelius	?	Berzelius obtained the oxide of a new earth in thorite.[68]
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.[69]
68	Erbium	1842		?	C.G.Mosander	?	Mosander managed to split the old yttria into yttria proper and erbia, and later terbia too.[70]
65	Terbium	1842		1842	C.G.Mosander	C.G.Mosander	In 1842 Mosander split yttria into two more earths, erbia and terbia[71]
44	Ruthenium	1807		1844	J.Sniadecki	J.Sniadecki	Sniadecki isolated the element in 1807 but his work was not ratified. Gottfried Wilhelm Osann 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.[72]
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.[73] The pure metal was eventually isolated in 1882 by Setterberg.[74]
37	Rubidium	1861		?	R.W.Bunsen & G.R.Kirchhoff	Robert Bunsen	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.[75]
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.[76]
49	Indium	1863		1867	F.Reich & H.T.Richter	T.Richter	Reich and Richter First identified it in sphalerite by its bright indigo-blue spectroscopic emission line. Richter isolated the metal several years later.[77]
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 cleveite about the same time.[78]
		1869			D.I.Mendeleev		Mendeleev arranges the 63 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.[79]
70	Ytterbium	1878		?	J.C.G. de Marignac	?	On October 22, 1878, Marignac reported splitting terbia into two new earths, terbia proper and ytterbia.[80]
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.[81]
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.[82]
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.[83]
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.[84]
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.[85]
59	Praseodymium	1885		?	C.A.von Welsbach	?	Von Welsbach discovered two new distinct elements in ceria: praseodymium and neodymium.[86]
60	Neodymium	1885		?	C.A.von Welsbach	?	Von Welsbach discovered two new distinct elements in ceria: praseodymium and neodymium.[87]
66	Dysprosium	1886		?	P.E.L. de Boisbaudran	?	De Boisbaudran found a new earth in erbia.[87]
32	Germanium	1886		?	C.A.Winkler	?	In February 1886 Winkler found in argyrodite the eka-silicon that Mendeleev had predicted in 1871.[88]
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.[89]
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.[90]
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.[91]
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.[91]
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.[92]
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.[93]
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.[94]
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.[95][96]
89	Actinium	1899		1899	A.-L.Debierne	A.-L.Debierne	Debierne obtained from pitchblende a substance that had similar properties to thorium.[97]
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.[98]
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.[99]
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.[100] In 1922 Walter Noddack, Ida Eva Tacke and Otto Berg announced its separation from gadolinite and gave it the present name.[57]
72	Hafnium	1911		1922	G.Urbain, V.I.Vernadsky	D.Coster & G. von Hevesy	Urbain claimed to have found the element in rare-earth residues, while Vernadsky independently found it in orthite. Neither claims was confirmed due to the World War I. After it, Coster and Hevesy found it by X-ray spectroscopic analysis in Norwegian zircon.[101] 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.[102] Originally isolated in 1900 by William Crookes.[103]
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 cyclotron, the first synthetic element to be discovered. It had been predicted by Mendeleev in 1871 as eka-manganese.[104][105]
87	Francium	1939		1939	M.Perey	M.Perey	Perey discovered it as a decay product of 227Ac.[106] 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.[107] 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.[108]
94	Plutonium	1940-1		?	G.T.Seaborg, Arthur C. Wahl, J.K.Kennedy, E.M.McMillan	?	Prepared by bombardment of uranium with deuterons.[109]
95	Americium	1944		?	G.T.Seaborg, R.A.James, L.O.Morgan & A.Ghiorso	?	Prepared by irradiating plutonium with neutrons during the Manhattan Project.[110]
96	Curium	1944		?	G.T.Seaborg, R.A.James, A.Ghiorso	?	Prepared by bombarding plutonium with alpha particles during the Manhattan Project[111]
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.[86]
97	Berkelium	1949		?	S.G.Thompson, A.Ghiorso, G.T.Seaborg (University of California, Berkeley)	?	Created by bombardment of americium with alpha particles.[112]
98	Californium	1950		?	S.G.Thompson, K.Street,Jr., A.Ghiorso, G.T.Seaborg (University of California, Berkeley)	?	Bombardment of curium with alpha particles.[113]
99	Einsteinium	1952		1952	A.Ghiorso et al. (Argonne Laboratory, Los Alamos Laboratory, and University of California, Berkeley)		Formed in the first thermonuclear explosion in November 1952, by irradiation of uranium with neutrons and kept secret for several years.[114]
100	Fermium	1952		?	A.Ghiorso et al. (Argonne Laboratory, Los Alamos Laboratory, and University of California, Berkeley)		Formed in the first thermonuclear explosion in November 1952, by irradiation of uranium with neutrons and kept secret for several years.[115]
101	Mendelevium	1955		?	A.Ghiorso, B.G.Harvey, G.R.Choppin, S.G.Thompson, G.T.Seaborg	?	Prepared by bombardment of einsteinium with helium.[116]
102	Nobelium	1958		?	A.Ghiorso, T.Sikkeland, J.R.Walton, G.T.Seaborg	?	First prepared by bombardment of curium with carbon atoms.[117]
103	Lawrencium	1961		?	A.Ghiorso, T.Sikkeland, A.E.Larsh, R.M.Latimer	?	First prepared by bombardment of californium with boron atoms.[118]
104	Rutherfordium	1968		?	A.Ghiorso, M.Nurmia, J.Harris, K.Eskola, P.Eskola	?	Prepared by bombardment of californium with carbon atoms.[119]
105	Dubnium	1970		?	A.Ghiorso, M.Nurmia, K.Eskola, J.Harris, P.Eskola	?	By bombardment of californium with carbon atoms.[120]
106	Seaborgium	1974		?	A.Ghiorso, J.Nitschke, J.Alonso, C.Alonso, M.Nurmia, G. Seaborg, K.Hulet, R.Lougheed	?	Collisions of californium-249 with oxygen atoms.[121]
107	Bohrium	1981		?	G.Münzenberg et al. GSI in Darmstadt	?	Obtained by bombarding bismuth with chromium.[122]
109	Meitnerium	1982		?	G.Münzenberg, P.Armbruster et al. GSI in Darmstadt	?	Bombardment of bismuth with iron atoms.[123]
108	Hassium	1984		?	G.Münzenberg, P.Armbruster et al. at GSI in Darmstadt	?	Bombardment of lead with iron atoms[124]
110	Darmstadtium	1994		?	S.Hofmann et al. at GSI in Darmstadt	?	Bombardment of lead with nickel.[125]
111	Roentgenium	1994		?	S.Hofmann et al. at GSI in Darmstadt	?	Bombardment of bismuth with nickel.[126]
112	Copernicium	1996		?	S.Hofmann et al. at GSI in Darmstadt	?	Bombardment of lead with zinc.[127][128]

[edit] Recent discoveries

Confirmed discoveries (Unofficial by IUPAC)

Z	Name	Discovery year	Discoverer	Notes
114	Ununquadium	1999	Joint Institute for Nuclear Research in Dubna	Bombardment of plutonium with calcium[129]

Unconfirmed discoveries

Z	Name	Discovery year	Discoverer	Notes
116	Ununhexium	2000	Joint Institute for Nuclear Research in Dubna	Bombardment of curium with calcium[130]
118	Ununoctium	2002	Joint Institute for Nuclear Research in Dubna and Lawrence Livermore National Laboratory	Bombardment of californium with calcium[131]
113	Ununtrium	2003	Joint Institute for Nuclear Research in Dubna and Lawrence Livermore National Laboratory	Decay of ununpentium[132]
115	Ununpentium	2003	Joint Institute for Nuclear Research in Dubna and Lawrence Livermore National Laboratory	Bombardment of americium with calcium[132]
117	Ununseptium	2009	Joint Institute for Nuclear Research in Dubna and Lawrence Livermore National Laboratory	Bombardment of berkelium with calcium[133]