|
Actinium
|
Ac
|
89
|
(227)
|
Actinide series
|
1899
|
André Debierne
|
|
Aluminum
|
Al
|
13
|
26.9815
|
Other metals
|
1824
|
Hans Oersted (also attributed to Friedrich Wöhler 1827)
|
|
Americium
|
Am
|
95
|
243
|
Actinide series
|
1944
|
Glenn Seaborg, Ralph James, Leon Morgan, and Albert Ghiorso
|
|
Antimony
|
Sb
|
51
|
121.760
|
Other metals
|
prehistoric
|
unknown
|
|
Argon
|
Ar
|
18
|
39.948
|
Noble gases
|
1894
|
John Rayleigh and William Ramsay
|
|
Arsenic
|
As
|
33
|
74.9216
|
Nonmetals
|
prehistoric
|
unknown
|
|
Astatine
|
At
|
85
|
(210)
|
Halogens
|
1940
|
Dale R. Corson, K. R. MacKenzie, and Emilio Segrè
|
|
Barium
|
Ba
|
56
|
137.328
|
Alkaline earth metals
|
1808
|
Humphry Davy
|
|
Berkelium
|
Bk
|
97
|
(247)
|
Actinide series
|
1949
|
Glenn Seaborg, Stanley Thompson, and Albert Ghiorso
|
|
Beryllium
|
Be
|
4
|
9.0122
|
Alkaline earth metals
|
1798
|
Louis-Nicolas Vauquelin (isolated by Friedrich Wöhler and Antoine-Alexandre-Brutus Bussy 1828)
|
|
Bismuth
|
Bi
|
83
|
208.9804
|
Other metals
|
prehistoric
|
unknown
|
|
Bohrium
|
Bh
|
107
|
(262)
|
Transition metals
|
1976
|
Georgii Flerov and Yuri Oganessian (confirmed by German scientist Peter Armbruster and coworkers)
|
|
Boron
|
B
|
5
|
10.81
|
Nonmetals
|
1808
|
Humphry Davy, and independently by Joseph Gay-Lussac and Louis-Jacques Thénard
|
|
Bromine
|
Br
|
35
|
79.904
|
Halogens
|
1826
|
Antoine-Jérôme Balard
|
|
Cadmium
|
Cd
|
48
|
112.412
|
Transition metals
|
1817
|
Friedrich Strohmeyer
|
|
Calcium
|
Ca
|
20
|
40.078
|
Alkaline earth metals
|
1808
|
Humphry Davy
|
|
Californium
|
Cf
|
98
|
(251)
|
Actinide series
|
1950
|
Glenn Seaborg, Stanley Thompson, Kenneth Street, Jr., and Albert Ghiorso
|
|
Carbon
|
C
|
6
|
12.011
|
Nonmetals
|
prehistoric
|
unknown
|
|
Cerium
|
Ce
|
58
|
140.115
|
Lanthanide series
|
1804
|
Jöns Berzelius and Wilhelm Hisinger, and independently by Martin Klaproth
|
|
Cesium
|
Cs
|
55
|
132.9054
|
Alkali metals
|
1860
|
Robert Bunsen and Gustav Kirchhoff
|
|
Chlorine
|
Cl
|
17
|
35.4528
|
Halogens
|
1774
|
Karl Scheele
|
|
Chromium
|
Cr
|
24
|
51.9962
|
Transition metals
|
1797
|
Louis-Nicolas Vauquelin
|
|
Cobalt
|
Co
|
27
|
58.9332
|
Transition metals
|
1730
|
Georg Brandt
|
|
Copper
|
Cu
|
29
|
63.546
|
Transition metals
|
prehistoric
|
unknown
|
|
Curium
|
Cm
|
96
|
(247)
|
Actinide series
|
1944
|
Glenn Seaborg, Ralph James, and Albert Ghiorso
|
|
Darmstadtium
|
Ds
|
110
|
(271)
|
Transition metals
|
1994
|
team at the Heavy-Ion Research Laboratory, Darmstadt, Germany
|
|
Dubnium
|
Db
|
105
|
(262)
|
Transition metals
|
1970
|
claimed by Albert Ghiorso and coworkers (disputed by Soviet workers)
|
|
Dysprosium
|
Dy
|
66
|
162.500
|
Lanthanide series
|
1886
|
Paul Lecoq de Boisbaudran
|
|
Einsteinium
|
Es
|
99
|
(252)
|
Actinide series
|
1952
|
Albert Ghiorso and coworkers
|
|
Erbium
|
Er
|
68
|
167.26
|
Lanthanide series
|
1843
|
Carl Mosander
|
|
Europium
|
Eu
|
63
|
151.966
|
Lanthanide series
|
1901
|
Eugène Demarçay
|
|
Fermium
|
Fm
|
100
|
(257)
|
Actinide series
|
1955
|
Albert Ghiorso and coworkers
|
|
Fluorine
|
F
|
9
|
18.9984
|
Halogens
|
1771
|
Karl Scheele (isolated by Henri Moissan 1886)
|
|
Francium
|
Fr
|
87
|
(223)
|
Alkali metals
|
1939
|
Marguérite Perey
|
|
Gadolinium
|
Gd
|
64
|
157.25
|
Lanthanide series
|
1886
|
Paul Lecoq de Boisbaudran
|
|
Gallium
|
Ga
|
31
|
69.723
|
Other metals
|
1875
|
Paul Lecoq de Boisbaudran
|
|
Germanium
|
Ge
|
32
|
72.61
|
Other metals
|
1886
|
Clemens Winkler
|
|
Gold
|
Au
|
79
|
196.9665
|
Transition metals
|
prehistoric
|
unknown
|
|
Hafnium
|
Hf
|
72
|
178.49
|
Transition metals
|
1913
|
Dirk Coster and Georg von Hevesy
|
|
Hassium
|
Hs
|
108
|
(263)
|
Transition metals
|
1984
|
Peter Armbruster and coworkers
|
|
Helium
|
He
|
2
|
4.0026
|
Noble gases
|
1868
|
Pierre Janssen
|
|
Holmium
|
Ho
|
67
|
164.9303
|
Lanthanide series
|
1879
|
Per Cleve
|
|
Hydrogen
|
H
|
1
|
1.0079
|
Nonmetals
|
1766
|
Henry Cavendish
|
|
Indium
|
In
|
49
|
114.818
|
Other metals
|
1863
|
Ferdinand Reich and Hieronymus Richter
|
|
Iodine
|
I
|
53
|
126.9045
|
Halogens
|
1811
|
Bernard Courtois
|
|
Iridium
|
Ir
|
77
|
192.217
|
Transition metals
|
1804
|
Smithson Tennant
|
|
Iron
|
Fe
|
26
|
55.845
|
Transition metals
|
prehistoric
|
unknown
|
|
Krypton
|
Kr
|
36
|
83.798
|
Noble gases
|
1898
|
William Ramsay and Morris Travers
|
|
Lanthanum
|
La
|
57
|
138.9055
|
Lanthanide series
|
1839
|
Carl Mosander
|
|
Lawrencium
|
Lr
|
103
|
(260)
|
Transition metals
|
1961
|
Albert Ghiorso, Torbjørn Sikkeland, Almon Larsh, and Robert Latimer
|
|
Lead
|
Pb
|
82
|
207.2
|
Other metals
|
prehistoric
|
unknown
|
|
Lithium
|
Li
|
3
|
6.941
|
Alkali metals
|
1817
|
Johan Arfwedson
|
|
Lutetium
|
Lu
|
71
|
174.967
|
Transition metals
|
1907
|
Georges Urbain and Carl von Welsbach, independently of each other
|
|
Magnesium
|
Mg
|
12
|
24.3051
|
Alkaline earth metals
|
1755
|
Joseph Black (oxide isolated by Humphry Davy 1808; pure form isolated by Antoine-Alexandre-Brutus Bussy 1828)
|
|
Manganese
|
Mn
|
25
|
54.938
|
Transition metals
|
1774
|
Johann Gottlieb Gahn
|
|
Meitnerium
|
Mt
|
109
|
(268)
|
Transition metals
|
1982
|
Peter Armbruster and coworkers
|
|
Mendelevium
|
Md
|
101
|
(258)
|
Actinide series
|
1955
|
Albert Ghiorso, Bernard G. Harvey, Gregory Choppin, Stanley Thompson, and Glenn Seaborg
|
|
Mercury
|
Hg
|
80
|
200.59
|
Transition metals
|
prehistoric
|
unknown
|
|
Molybdenum
|
Mo
|
42
|
95.94
|
Transition metals
|
1781
|
named by Karl Scheele (isolated by Peter Jacob Hjelm 1782)
|
|
Neodymium
|
Nd
|
60
|
144.24
|
Lanthanide series
|
1885
|
Carl von Welsbach
|
|
Neon
|
Ne
|
10
|
20.1798
|
Noble gases
|
1898
|
William Ramsay and Morris Travers
|
|
Neptunium
|
Np
|
93
|
(237)
|
Actinide series
|
1940
|
Edwin McMillan and Philip Abelson
|
|
Nickel
|
Ni
|
28
|
58.6934
|
Transition metals
|
1751
|
Axel Cronstedt
|
|
Niobium
|
Nb
|
41
|
92.9064
|
Transition metals
|
1801
|
Charles Hatchett
|
|
Nitrogen
|
N
|
7
|
14.0067
|
Nonmetals
|
1772
|
Daniel Rutherford
|
|
Nobelium
|
No
|
102
|
(259)
|
Actinide series
|
1958
|
Albert Ghiorso, Torbjørn Sikkeland, J. R. Walton, and Glenn Seaborg
|
|
Osmium
|
Os
|
76
|
190.23
|
Transition metals
|
1804
|
Smithson Tennant
|
|
Oxygen
|
O
|
8
|
15.9994
|
Nonmetals
|
1774
|
Joseph Priestley and Karl Scheele, independently of each other
|
|
Palladium
|
Pd
|
46
|
106.42
|
Transition metals
|
1804
|
William Wollaston
|
|
Phosphorus
|
P
|
15
|
30.9738
|
Nonmetals
|
1674
|
Hennig Brand
|
|
Platinum
|
Pt
|
78
|
195.08
|
Transition metals
|
1557
|
Julius Scaliger
|
|
Plutonium
|
Pu
|
94
|
(244)
|
Actinide series
|
1940
|
Glenn Seaborg, Edwin McMillan, Joseph Kennedy, and Arthur Wahl
|
|
Polonium
|
Po
|
84
|
(209)
|
Other metals
|
1898
|
Marie and Pierre Curie
|
|
Potassium
|
K
|
19
|
39.0983
|
Alkali metals
|
1807
|
Humphry Davy
|
|
Praseodymium
|
Pr
|
59
|
140.908
|
Lanthanide series
|
1885
|
Carl von Welsbach
|
|
Promethium
|
Pm
|
61
|
(145)
|
Lanthanide series
|
1945
|
J. A. Marinsky, Lawrence Glendenin, and Charles Coryell
|
|
Protactinium
|
Pa
|
91
|
231.036
|
Actinide series
|
1913
|
Kasimir Fajans and O. Göhring
|
|
Radium
|
Ra
|
88
|
(226)
|
Alkaline earth metals
|
1898
|
Marie Curie
|
|
Radon
|
Rn
|
86
|
(222)
|
Noble gases
|
1900
|
Friedrich Dorn
|
|
Rhenium
|
Re
|
75
|
186.207
|
Transition metals
|
1925
|
Walter Noddack, Ida Tacke, and Otto Berg
|
|
Rhodium
|
Rh
|
45
|
102.9055
|
Transition metals
|
1804
|
William Wollaston
|
|
Rubidium
|
Rb
|
37
|
85.4678
|
Alkali metals
|
1861
|
Robert Bunsen and Gustav Kirchhoff
|
|
Ruthenium
|
Ru
|
44
|
101.07
|
Transition metals
|
1827
|
G. W. Osann (isolated by Karl Klaus 1844)
|
|
Rutherfordium
|
Rf
|
104
|
(261)
|
Transition metals
|
1969
|
claimed by U.S. scientist Albert Ghiorso and coworkers (disputed by Soviet workers)
|
|
Samarium
|
Sm
|
62
|
150.36
|
Lanthanide series
|
1879
|
Paul Lecoq de Boisbaudran
|
|
Scandium
|
Sc
|
21
|
44.9559
|
Transition metals
|
1876
|
Lars Nilson
|
|
Seaborgium
|
Sg
|
106
|
(266)
|
Transition metals
|
1974
|
claimed by Georgii Flerov and coworkers, and independently by Albert Ghiorso and coworkers
|
|
Selenium
|
Se
|
34
|
78.96
|
Nonmetals
|
1817
|
Jöns Berzelius
|
|
Silicon
|
Si
|
14
|
28.0855
|
Nonmetals
|
1823
|
Johan Arfwedson
|
|
Silver
|
Ag
|
47
|
107.8682
|
Transition metals
|
prehistoric
|
unknown
|
|
Sodium
|
Na
|
11
|
22.9898
|
Alkali metals
|
1807
|
Humphry Davy
|
|
Strontium
|
Sr
|
38
|
87.62
|
Alkaline earth metals
|
1808
|
Humphry Davy
|
|
Sulfur
|
S
|
16
|
32.067
|
Nonmetals
|
prehistoric
|
unknown
|
|
Tantalum
|
Ta
|
73
|
180.948
|
Transition metals
|
1802
|
Anders Ekeberg
|
|
Technetium
|
Tc
|
43
|
(98)
|
Transition metals
|
1937
|
Carlo Perrier and Emilio Segrè
|
|
Tellurium
|
Te
|
52
|
127.60
|
Nonmetals
|
1782
|
Franz Müller
|
|
Terbium
|
Tb
|
65
|
158.9253
|
Lanthanide series
|
1843
|
Carl Mosander
|
|
Thallium
|
Tl
|
81
|
204.3833
|
Other metals
|
1861
|
William Crookes (isolated by William Crookes and Claude August Lamy, independently of each other, in 1862)
|
|
Thorium
|
Th
|
90
|
232.0381
|
Actinide series
|
1828
|
Jöns Berzelius
|
|
Thulium
|
Tm
|
69
|
168.9342
|
Lanthanide series
|
1879
|
Per Cleve
|
|
Tin
|
Sn
|
50
|
118.711
|
Other metals
|
prehistoric
|
unknown
|
|
Titanium
|
Ti
|
22
|
47.867
|
Transition metals
|
1790
|
William Gregor
|
|
Tungsten
|
W
|
74
|
183.84
|
Transition metals
|
1783
|
isolated by Juan José Elhuyar and Fausto Elhuyar
|
|
Ununbium
|
Uub
|
112
|
(277)
|
Transition metals
|
1996
|
team at the Heavy-Ion Research Laboratory, Darmstadt, Germany
|
|
Ununhexium
|
Uuh
|
116
|
(292)
|
Other metals
|
2000
|
team at the Joint Institute for Nuclear Research, Dubna, Russia
|
|
Ununoctium
|
Uuo
|
118
|
(294)
|
Noble gases
|
2006
|
team at the Joint Institute for Nuclear Research, Dubna, Russia
|
|
Ununpentium
|
Uup
|
115
|
(288)
|
Other metals
|
2004
|
team at the Joint Institute for Nuclear Research, Dubna, Russia
|
|
Ununquadium
|
Uuq
|
114
|
(285)
|
Other metals
|
1998
|
team at the Joint Institute for Nuclear Research, Dubna, Russia
|
|
Ununtrium
|
Uut
|
113
|
(284)
|
Other metals
|
2004
|
team at the Joint Institute for Nuclear Research, Dubna, Russia
|
|
Roentgenium
|
Rg
|
111
|
(272)
|
Transition metals
|
1994
|
team at the Heavy-Ion Research Laboratory, Darmstadt, Germany
|
|
Uranium
|
U
|
92
|
238.0289
|
Actinide series
|
1789
|
Martin Klaproth (isolated by Eugène Péligot 1841)
|
|
Vanadium
|
V
|
23
|
50.9415
|
Transition metals
|
1801
|
Andrés del Rio (disputed), or Nils Sefström 1830
|
|
Xenon
|
Xe
|
54
|
131.29
|
Noble gases
|
1898
|
William Ramsay and Morris Travers
|
|
Ytterbium
|
Yb
|
70
|
173.04
|
Lanthanide series
|
1878
|
Jean Charles de Marignac
|
|
Yttrium
|
Y
|
39
|
88.906
|
Transition metals
|
1794
|
Johan Gadolin
|
|
Zinc
|
Zn
|
30
|
65.409
|
Transition metals
|
prehistoric
|
unknown
|
|
Zirconium
|
Zr
|
40
|
91.224
|
Transition metals
|
1789
|
Martin Klaproth
|
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