1
1
H
1.008
3
Li
6.94
11
Na
22.990
19
K
39.098
37
Rb
85.468
55
Cs
132.91
87
Fr
(223)
2
4
Be
9.0122
12
Mg
24.305
20
Ca
40.078
38
Sr
87.62
56
Ba
137.33
88
Ra
(226)
3
21
Sc
44.956
39
Y
88.902
57-71
89-103
4
22
Ti
47.867
40
Zr
91.224
72
Hf
178.49
104
Rf
(267)
5
23
V
50.942
41
Nb
92.906
73
Ta
180.95
105
Db
(268)
6
24
Cr
51.996
42
Mo
95.95
74
W
183.84
106
Sg
(269)
7
25
Mn
54.938
43
Tc
(98)
75
Re
186.21
107
Bh
(270)
8
26
Fe
55.845
44
Ru
101.07
76
Os
190.23
108
Hs
(270)
9
27
Co
58.933
45
Rh
102.91
77
Ir
192.22
109
Mt
(278)
10
28
Ni
58.693
46
Pd
106.42
78
Pt
195.08
110
Ds
(281)
11
29
Cu
63.546
47
Ag
107.87
79
Au
196.97
111
Rg
(282)
12
30
Zn
65.38
48
Cd
112.41
80
Hg
200.59
112
Cn
(285)
13
5
B
10.81
13
Al
26.982
31
Ga
69.723
49
In
114.82
81
Tl
204.38
113
Nh
(286)
14
6
C
12.011
14
Si
28.085
32
Ge
72.630
50
Sn
118.71
82
Pb
207.2
114
Fl
(289)
15
7
N
14.007
15
P
30.974
33
As
74.922
51
Sb
121.76
83
Bi
208.98
115
Mc
(290)
16
8
O
15.999
16
S
32.06
34
Se
78.971
52
Te
127.60
84
Po
(209)
116
Lv
(293)
17
9
F
18.998
17
Cl
35.45
35
Br
79.904
53
I
126.90
85
At
(210)
117
Ts
(294)
18
2
He
4.0026
10
Ne
20.180
18
Ar
39.948
36
Kr
83.798
54
Xe
131.29
86
Rn
(222)
118
Og
(294)
57
La
138.91
89
Ac
(227)
58
Ce
140.12
90
Th
232.04
59
Pr
140.91
91
Pa
231.04
60
Nd
144.24
92
U
238.03
61
Pm
(145)
93
Np
(237)
62
Sm
150.36
94
Pu
(244)
63
Eu
151.96
95
Am
(243)
64
Gd
157.25
96
Cm
(247)
65
Tb
158.93
97
Bk
(247)
66
Dy
162.50
98
Cf
(251)
67
Ho
164.93
99
Es
(252)
68
Er
167.26
100
Fm
(257)
69
Tm
168.93
101
Md
(258)
70
Yb
173.05
102
No
(259)
71
Lu
174.97
103
Lr
(266)
1
H
1.008
Hydrogen
Hydrogen is the chemical element with the symbol H and atomic number 1. With a standard atomic weight of 1.008, hydrogen is the lightest element in the periodic table. Hydrogen is the most abundant chemical substance in the Universe, constituting roughly 75% of all baryonic mass.
3
Li
6.94
Lithium
Lithium is a chemical element with the symbol Li and atomic number 3. It is a soft, silvery-white alkali metal. Under standard conditions, it is the lightest metal and the lightest solid element.
11
Na
22.990
Sodium
Sodium is a chemical element with the symbol Na and atomic number 11. It is a soft, silvery-white, highly reactive metal. Sodium is an alkali metal, being in group 1 of the periodic table, because it has a single electron in its outer shell, which it readily donates, creating a positively charged ion—the Na+ cation.
19
K
39.098
Potassium
Potassium is a chemical element with the symbol K and atomic number 19. Potassium is a silvery-white metal that is soft enough to be cut with a knife with little force. Potassium metal reacts rapidly with atmospheric oxygen to form flaky white potassium peroxide in only seconds of exposure.
37
Rb
85.468
Rubidium
Rubidium is a chemical element with the symbol Rb and atomic number 37. Rubidium is a very soft, silvery-white metal in the alkali metal group. Rubidium metal shares similarities to potassium metal and caesium metal in physical appearance, softness and conductivity.
55
Cs
132.91
Caesium
Caesium is a chemical element with the symbol Cs and atomic number 55. It is a soft, silvery-golden alkali metal with a melting point of 28.5°C, which makes it one of only five elemental metals that are liquid at or near room temperature.
87
Fr
(223)
Francium
Francium is a chemical element with the symbol Fr and atomic number 87. Prior to its discovery, it was referred to as eka-caesium. It is extremely radioactive; its most stable isotope, francium-223, has a half-life of only 22 minutes.
4
Be
9.0122
Beryllium
Beryllium is a chemical element with the symbol Be and atomic number 4. It is a relatively rare element in the universe, usually occurring as a product of the spallation of larger atomic nuclei that have collided with cosmic rays. Within the cores of stars, beryllium is depleted as it is fused into heavier elements.
12
Mg
24.305
Magnesium
Magnesium is a chemical element with the symbol Mg and atomic number 12. It is a shiny gray solid which bears a close physical resemblance to the other five elements in the second column of the periodic table.
20
Ca
40.078
Calcium
Calcium is a chemical element with the symbol Ca and atomic number 20. As an alkaline earth metal, calcium is a reactive metal that forms a dark oxide-nitride layer when exposed to air. Its physical and chemical properties are most similar to its heavier homologues strontium and barium.
38
Sr
87.62
Strontium
Strontium is the chemical element with the symbol Sr and atomic number 38. An alkaline earth metal, strontium is a soft silver-white yellowish metallic element that is highly chemically reactive. The metal forms a dark oxide layer when it is exposed to air.
56
Ba
137.33
Barium
Barium is a chemical element with the symbol Ba and atomic number 56. It is the fifth element in group 2 and is a soft, silvery alkaline earth metal. Because of its high chemical reactivity, barium is never found in nature as a free element.
88
Ra
(226)
Radium
Radium is a chemical element with the symbol Ra and atomic number 88. It is the sixth element in group 2 of the periodic table, also known as the alkaline earth metals. Pure radium is silvery-white, but it readily reacts with nitrogen on exposure to air, forming a black surface layer of radium nitride.
21
Sc
44.956
Scandium
Scandium is a chemical element with the symbol Sc and atomic number 21. A silvery-white metallic d-block element, it has historically been classified as a rare-earth element, together with yttrium and the lanthanides. It was discovered in 1879 by spectral analysis of the minerals euxenite and gadolinite from Scandinavia.
39
Y
88.902
Yttrium
Yttrium is a chemical element with the symbol Y and atomic number 39. It is a silvery-metallic transition metal chemically similar to the lanthanides and has often been classified as a rare-earth element. Yttrium is almost always found in combination with lanthanide elements in rare-earth minerals, and is never found in nature as a free element.
22
Ti
47.867
Titanium
Titanium is a chemical element with the symbol Ti and atomic number 22. It is a lustrous transition metal with a silver color, low density, and high strength. Titanium is resistant to corrosion in sea water, aqua regia, and chlorine.
40
Zr
91.224
Zirconium
Zirconium is a chemical element with the symbol Zr and atomic number 40. The name zirconium is taken from the name of the mineral zircon, the most important source of zirconium.
72
Hf
178.49
Hafnium
Hafnium is a chemical element with the symbol Hf and atomic number 72. A lustrous, silvery gray, tetravalent transition metal, hafnium chemically resembles zirconium and is found in many zirconium minerals.
104
Rf
(267)
Rutherfordium
Rutherfordium is a synthetic chemical element with the symbol Rf and atomic number 104, named after New Zealand physicist Ernest Rutherford. As a synthetic element, it is not found in nature and can only be created in a laboratory. It is radioactive; the most stable known isotope, has a half-life of approximately 1.3 hours.
23
V
50.942
Vanadium
Vanadium is a chemical element with the symbol V and atomic number 23. It is a hard, silvery-grey, ductile, malleable transition metal. The elemental metal is rarely found in nature, but once isolated artificially, the formation of an oxide layer somewhat stabilizes the free metal against further oxidation.
41
Nb
92.906
Niobium
Niobium, formerly known as columbium, is a chemical element with the symbol Nb and atomic number 41. Niobium is a light grey, crystalline, and ductile transition metal. Pure Niobium has a hardness similar to that of pure titanium, and it has similar ductility to iron.
73
Ta
180.95
Tantalum
Tantalum is a chemical element with the symbol Ta and atomic number 73. Previously known as tantalium, its name comes from Tantalus, a villain from Greek mythology. Tantalum is a rare, hard, blue-gray, lustrous transition metal that is highly corrosion-resistant.
105
Db
(268)
Dubnium
Dubnium is a synthetic chemical element with the symbol Db and atomic number 105. Dubnium is highly radioactive: the most stable known isotope, dubnium-268, has a half-life of about 28 hours. This greatly limits the extent of research on dubnium.
24
Cr
51.996
Chromium
Chromium is a chemical element with the symbol Cr and atomic number 24. It is the first element in group 6. It is a steely-grey, lustrous, hard and brittle transition metal. Chromium is also the main additive in stainless steel, to which it adds anti-corrosive properties.
42
Mo
95.95
Molybdenum
Molybdenum is a chemical element with the symbol Mo and atomic number 42. The name is from Neo-Latin molybdaenum, since its ores were confused with lead ores. Molybdenum minerals have been known throughout history, but the element was discovered in 1778 by Carl Wilhelm Scheele.
74
W
183.84
Tungsten
Tungsten, or wolfram, is a chemical element with the symbol W and atomic number 74. The name tungsten comes from the former Swedish name for the tungstate mineral scheelite, tung sten or "heavy stone".
106
Sg
(269)
Seaborgium
Seaborgium is a synthetic chemical element with the symbol Sg and atomic number 106. It is named after the American nuclear chemist Glenn T. Seaborg. As a synthetic element, it can be created in a laboratory but is not found in nature. It is also radioactive; the most stable known isotope, 269Sg, has a half-life of approximately 14 minutes.
25
Mn
54.938
Manganese
Manganese is a chemical element with the symbol Mn and atomic number 25. It is not found as a free element in nature; it is often found in minerals in combination with iron. Manganese is a transition metal with important industrial alloy uses, particularly in stainless steels.
43
Tc
(98)
Technetium
Technetium is a chemical element with the symbol Tc and atomic number 43. It is the lightest element whose isotopes are all radioactive; none are stable, excluding the fully ionized state of 97Tc. Nearly all technetium is produced as a synthetic element, and only about 18,000 tons can be found at any given time in the Earth's crust.
75
Re
186.21
Rhenium
Rhenium is a chemical element with the symbol Re and atomic number 75. It is a silvery-gray, heavy, third-row transition metal in group 7 of the periodic table. With an estimated average concentration of 1 part per billion, rhenium is one of the rarest elements in the Earth's crust.
107
Bh
(270)
Bohrium
Bohrium is a synthetic chemical element with the symbol Bh and atomic number 107. It is named after Danish physicist Niels Bohr. As a synthetic element, it can be created in a laboratory but is not found in nature.
26
Fe
55.845
Iron
Iron is a chemical element with symbol Fe and atomic number 26. It is a metal, that belongs to the first transition series and group 8 of the periodic table. It is by mass the most common element on Earth, forming much of Earth's outer and inner core. It is the fourth most common element in the Earth's crust.
44
Ru
101.07
Ruthenium
Ruthenium is a chemical element with the symbol Ru and atomic number 44. It is a rare transition metal belonging to the platinum group of the periodic table. Like the other metals of the platinum group, ruthenium is inert to most other chemicals.
76
Os
190.23
Osmium
Osmium is a chemical element with the symbol Os and atomic number 76. It is a hard, brittle, bluish-white transition metal in the platinum group that is found as a trace element in alloys, mostly in platinum ores.
108
Hs
(270)
Hassium
Hassium is a chemical element with the symbol Hs and atomic number 108. It is not known to occur in nature and has only been made in laboratories in miniscule quantities. It is highly radioactive: the most stable known isotope, has a half-life of approximately 16 seconds.
27
Co
58.693
Cobalt
Cobalt is a chemical element with the symbol Co and atomic number 27. Like nickel, cobalt is found in the Earth's crust only in chemically combined form, save for small deposits found in alloys of natural meteoric iron. The free element, produced by reductive smelting, is a hard, lustrous, silver-gray metal.
45
Rh
102.91
Rhodium
Rhodium is a chemical element with the symbol Rh and atomic number 45. It is a rare, silvery-white, hard, corrosion-resistant, and chemically inert transition metal. It is a noble metal and a member of the platinum group. It has only one naturally occurring isotope.
77
Ir
192.22
Iridium
Iridium is a chemical element with the symbol Ir and atomic number 77. A very hard, brittle, silvery-white transition metal of the platinum group, iridium is the second-densest metal with a density of 22.56 g/cm3 as defined by experimental X-ray crystallography.
109
Mt
(278)
Meitnerium
Meitnerium is a synthetic chemical element with the symbol Mt and atomic number 109. It is an extremely radioactive synthetic element. The most stable known isotope, meitnerium-278, has a half-life of 4.5 seconds, although the unconfirmed meitnerium-282 may have a longer half-life of 67 seconds.
28
Ni
58.693
Nickel
Nickel is a chemical element with the symbol Ni and atomic number 28. It is a silvery-white lustrous metal with a slight golden tinge. Nickel belongs to the transition metals and is hard and ductile.
46
Pd
106.42
Palladium
Palladium is a chemical element with the symbol Pd and atomic number 46. It is a rare and lustrous silvery-white metal discovered in 1803 by William Hyde Wollaston.
78
Pt
195.08
Platinum
Platinum is a chemical element with the symbol Pt and atomic number 78. It is a dense, malleable, ductile, highly unreactive, precious, silverish-white transition metal. Its name is derived from the Spanish term platino, meaning "little silver".
110
Ds
(281)
Darmstadtium
Darmstadtium is a synthetic chemical element with the symbol Ds and atomic number 110. It is an extremely radioactive synthetic element. The most stable known isotope, darmstadtium-281, has a half-life of approximately 12.7 seconds.
29
Cu
63.546
Copper
Copper is a chemical element with the symbol Cu and atomic number 29. It is a soft, malleable, and ductile metal with very high thermal and electrical conductivity. A freshly exposed surface of pure copper has a pinkish-orange color.
47
Ag
107.87
Silver
Silver is a chemical element with the symbol Ag and atomic number 47. A soft, white, lustrous transition metal, it exhibits the highest electrical conductivity, thermal conductivity, and reflectivity of any metal.
79
Au
196.97
Gold
Gold is a chemical element with the symbol Au and atomic number 79, making it one of the higher atomic number elements that occur naturally. In its purest form, it is a bright, slightly reddish yellow, dense, soft, malleable, and ductile metal.
111
Rg
(282)
Roentgenium
Roentgenium is a chemical element with the symbol Rg and atomic number 111. It is an extremely radioactive synthetic element that can be created in a laboratory but is not found in nature.
30
Zn
65.38
Zinc
Zinc is a chemical element with the symbol Zn and atomic number 30. Zinc is a slightly brittle metal at room temperature and has a blue-silvery appearance when oxidation is removed. It is the first element in group 12 of the periodic table.
48
Cd
112.41
Cadmium
Cadmium is a chemical element with the symbol Cd and atomic number 48. This soft, silvery-white metal is chemically similar to the two other stable metals in group 12, zinc and mercury.
80
Hg
200.59
Mercury
Mercury is a chemical element with the symbol Hg and atomic number 80. It is commonly known as quicksilver and was formerly named hydrargyrum. A heavy, silvery d-block element, mercury is the only metallic element that is liquid.
112
Cn
(285)
Copernicium
Copernicium is a synthetic chemical element with the symbol Cn and atomic number 112. Its known isotopes are extremely radioactive, and have only been created in a laboratory. The most stable known isotope, copernicium-285, has a half-life of approximately 28 seconds.
5
B
10.81
Boron
Boron is a chemical element with the symbol B and atomic number 5. Produced entirely by cosmic ray spallation and supernovae and not by stellar nucleosynthesis, it is a low-abundance element in the Solar system and in the Earth's crust.
13
Al
26.982
Aluminium
Aluminium is a chemical element with the symbol Al and atomic number 13. It is a silvery-white, soft, non-magnetic and ductile metal in the boron group. By mass, aluminium makes up about 8% of the Earth's crust.
31
Ga
69.723
Gallium
Gallium is a chemical element with the symbol Ga and atomic number 31. Elemental gallium is a soft, silvery blue metal at standard temperature and pressure; however in its liquid state it becomes silvery white.
49
In
114.82
Indium
Indium is a chemical element with the symbol In and atomic number 49. Indium is the softest metal that is not considered to be an alkali metal. It is a silvery-white metal that resembles tin in appearance. It is a post-transition metal that makes up 0.21 parts per million of the Earth's crust.
81
Tl
204.38
Thallium
Thallium is a chemical element with the symbol Tl and atomic number 81. It is a gray post-transition metal that is not found free in nature. When isolated, thallium resembles tin, but discolors when exposed to air.
113
Nh
(286)
Nihonium
Nihonium is a synthetic chemical element with the symbol Nh and atomic number 113. It is extremely radioactive; its most stable known isotope, nihonium-286, has a half-life of about 10 seconds. In the periodic table, nihonium is a transactinide element in the p-block.
6
C
12.011
Carbon
Carbon is a chemical element with the symbol C and atomic number 6. It is nonmetallic and tetravalent—making four electrons available to form covalent chemical bonds. It belongs to group 14 of the periodic table.
14
Si
28.085
Silicon
Silicon is a chemical element with the symbol Si and atomic number 14. It is a hard and brittle crystalline solid with a blue-grey metallic lustre; and it is a tetravalent metalloid and semiconductor.
32
Ge
72.630
Germanium
Germanium is a chemical element with the symbol Ge and atomic number 32. It is a lustrous, hard-brittle, grayish-white metalloid in the carbon group, chemically similar to its group neighbours silicon and tin.
50
Sn
118.71
Tin
Tin is a chemical element with the symbol Sn and atomic number 50. Tin is a silvery metal that characteristicly has a faint yellow hue. Tin, like indium, is soft enough to be cut without much force.
82
Pb
207.2
Lead
Lead is a chemical element with the symbol Pb and atomic number 82. It is a heavy metal that is denser than most common materials. Lead is soft and malleable, and also has a relatively low melting point.
114
Fl
(289)
Flerovium
Flerovium is a superheavy artificial chemical element with the symbol Fl and atomic number 114. It is an extremely radioactive synthetic element. The element is named after the Flerov Laboratory of Nuclear Reactions of the Joint Institute for Nuclear Research in Dubna, Russia, where the element was discovered in 1998.
7
N
14.007
Nitrogen
Nitrogen is the chemical element with the symbol N and atomic number 7. It was first discovered and isolated by Scottish physician Daniel Rutherford in 1772. Although Carl Wilhelm Scheele and Henry Cavendish had independently done so at about the same time, Rutherford is generally accorded the credit because his work was published first.
15
P
30.974
Phosphorus
Phosphorus is a chemical element with the symbol P and atomic number 15. Elemental phosphorus exists in two major forms, white phosphorus and red phosphorus, but because it is highly reactive, phosphorus is never found as a free element on Earth.
33
As
74.922
Arsenic
Arsenic is a chemical element with the symbol As and atomic number 33. Arsenic occurs in many minerals, usually in combination with sulfur and metals, but also as a pure elemental crystal. Arsenic is a metalloid. It has various allotropes, but only the gray form, which has a metallic appearance, is important to industry.
51
Sb
121.76
Antimony
Antimony is a chemical element with the symbol Sb and atomic number 51. A lustrous gray metalloid, it is found in nature mainly as the sulfide mineral stibnite.
83
Bi
208.98
Bismuth
Bismuth is a chemical element with the symbol Bi and atomic number 83. It is a pentavalent post-transition metal and one of the pnictogens with chemical properties resembling its lighter homologs arsenic and antimony. Elemental bismuth may occur naturally, although its sulfide and oxide form important commercial ores.
115
Mc
(290)
Moscovium
Moscovium is a synthetic chemical element with the symbol Mc and atomic number 115. It was first synthesized in 2003 by a joint team of Russian and American scientists at the Joint Institute for Nuclear Research (JINR) in Dubna, Russia.
8
O
15.999
Oxygen
Oxygen is the chemical element with the symbol O and atomic number 8, meaning its nucleus has 8 protons. The number of neutrons varies according to the isotope: the stable isotopes have 8, 9, or 10 neutrons.
16
S
32.06
Sulfur
Sulfur is a chemical element with the symbol S and atomic number 16. It is abundant, multivalent, and nonmetallic. Under normal conditions, sulfur atoms form cyclic octatomic molecules with a chemical formula. Elemental sulfur is a bright yellow, crystalline solid at room temperature.
34
Se
78.971
Selenium
Selenium is a chemical element with the symbol Se and atomic number 34. It is a nonmetal with properties that are intermediate between the elements above and below in the periodic table, sulfur and tellurium, and also has similarities to arsenic.
52
Te
127.60
Tellurium
Tellurium is a chemical element with the symbol Te and atomic number 52. It is a brittle, mildly toxic, rare, silver-white metalloid. Tellurium is chemically related to selenium and sulfur, all three of which are chalcogens. It is occasionally found in native form as elemental crystals.
84
Po
(209)
Polonium
Polonium is a chemical element with the symbol Po and atomic number 84. A rare and highly radioactive metal with no stable isotopes, polonium is chemically similar to selenium and tellurium, though its metallic character resembles that of its horizontal neighbors in the periodic table: thallium, lead, and bismuth.
116
Lv
(293)
Livermorium
Livermorium is a synthetic chemical element with the symbol Lv and has an atomic number of 116. It is an extremely radioactive element that has only been created in the laboratory and has not been observed in nature.
9
F
18.998
Fluorine
Fluorine is a chemical element with the symbol F and atomic number 9. It is the lightest halogen and exists as a highly toxic pale yellow diatomic gas at standard conditions. As the most electronegative element, it is extremely reactive, as it reacts with almost all other elements, except for helium and neon.
17
Cl
35.45
Chlorine
Chlorine is a chemical element with the symbol Cl and atomic number 17. The second-lightest of the halogens, it appears between fluorine and bromine in the periodic table and its properties are mostly intermediate between them.
35
Br
79.904
Bromine
Bromine is a chemical element with symbol Br and atomic number 35. It is the third-lightest halogen, and is a fuming red-brown liquid at room temperature that evaporates readily to form a similarly coloured gas. Its properties are thus intermediate between those of chlorine and iodine.
53
I
126.90
Iodine
Iodine is a chemical element with the symbol I and atomic number 53. The heaviest of the stable halogens, it exists as a lustrous, purple-black non-metallic solid at standard conditions that melts to form a deep violet liquid at 114 degrees Celsius, and boils to a violet gas at 184 degrees Celsius.
85
At
(210)
Astatine
Astatine is a radioactive chemical element with the symbol At and atomic number 85. It is the rarest naturally occurring element in the Earth's crust, occurring only as the decay product of various heavier elements. All of astatine's isotopes are short-lived; the most stable is astatine-210, with a half-life of 8.1 hours.
117
Ts
(294)
Tennessine
Tennessine is a synthetic chemical element with the symbol Ts and atomic number 117. It is the second-heaviest known element and the penultimate element of the 7th period of the periodic table.
2
He
4.0026
Helium
Helium is a chemical element with the symbol He and atomic number 2. It is a colorless, odorless, tasteless, non-toxic, inert, monatomic gas, the first in the noble gas group in the periodic table. Its boiling point is the lowest among all the elements.
10
Ne
20.180
Neon
Neon is a chemical element with the symbol Ne and atomic number 10. It is a noble gas.[10] Neon is a colorless, odorless, inert monatomic gas under standard conditions, with about two-thirds the density of air.
18
Ar
39.948
Argon
Argon is a chemical element with the symbol Ar and atomic number 18. It is in group 18 of the periodic table and is a noble gas. Argon is the third-most abundant gas in the Earth's atmosphere, at 0.934%.
36
Kr
83.798
Krypton
Krypton is a chemical element with the symbol Kr and atomic number 36. It is a colorless, odorless, tasteless noble gas that occurs in trace amounts in the atmosphere and is often used with other rare gases in fluorescent lamps. With rare exceptions, krypton is chemically inert.
54
Xe
131.29
Xenon
Xenon is a chemical element with the symbol Xe and atomic number 54. It is a colorless, dense, odorless noble gas found in Earth's atmosphere in trace amounts. Although generally unreactive, xenon can undergo a few chemical reactions such as the formation of xenon hexafluoroplatinate, the first noble gas compound to be synthesized.
86
Rn
(222)
Radon
Radon is a chemical element with the symbol Rn and atomic number 86. It is a radioactive, colorless, odorless, tasteless noble gas. It occurs naturally in minute quantities as an intermediate step in the normal radioactive decay chains through which thorium and uranium slowly decay into lead and various other short-lived radioactive elements.
118
Og
(294)
Oganesson
Oganesson is a synthetic chemical element with the symbol Og and atomic number 118. It was first synthesized in 2002 at the Joint Institute for Nuclear Research (JINR) in Dubna, near Moscow in Russia, by a joint team of Russian and American scientists.
57
La
138.91
Lanthanum
Lanthanum is a chemical element with the symbol La and atomic number 57. It is a soft, ductile, silvery-white metal that tarnishes slowly when exposed to air and is soft enough to be cut with a knife.
89
Ac
(227)
Actinium
Actinium is a chemical element with the symbol Ac and atomic number 89. It was first isolated by French chemist André-Louis Debierne in 1899. Friedrich Oskar Giesel later independently isolated it in 1902 and, unaware that it was already known, gave it the name emanium.
58
Ce
140.12
Cerium
Cerium is a chemical element with the symbol Ce and atomic number 58. Cerium is a soft, ductile and silvery-white metal that tarnishes when exposed to air, and it is soft enough to be cut with a knife.
90
Th
232.04
Thorium
Thorium is a weakly radioactive metallic chemical element with the symbol Th and atomic number 90. Thorium is silvery and tarnishes black when it is exposed to air, forming thorium dioxide; it is moderately hard, malleable, and has a high melting point.
59
Pr
140.91
Praseodymium
Praseodymium is a chemical element with the symbol Pr and atomic number 59. It is the third member of the lanthanide series and is traditionally considered to be one of the rare-earth metals. Praseodymium is a soft, silvery, malleable and ductile metal, valued for its magnetic, electrical, chemical, and optical properties.
91
Pa
231.04
Protactinium
Protactinium is a chemical element with the symbol Pa and atomic number 91. It is a dense, silvery-gray actinide metal which readily reacts with oxygen, water vapor and inorganic acids. It forms various chemical compounds in which protactinium is usually present in the oxidation state +5, but it can also assume +4 and even +3 or +2 states.
60
Nd
144.24
Neodymium
Neodymium is a chemical element with the symbol Nd and atomic number 60. Neodymium belongs to the lanthanide series and is a rare-earth element. It is a hard, slightly malleable silvery metal, that quickly tarnishes in air and moisture.
92
U
238.03
Uranium
Uranium is a chemical element with the symbol U and atomic number 92. It is a silvery-grey metal in the actinide series of the periodic table. A uranium atom has 92 protons and 92 electrons, of which 6 are valence electrons.
61
Pm
(145)
Promethium
Promethium is a chemical element with the symbol Pm and atomic number 61. All of its isotopes are radioactive; it is extremely rare, with only about 500–600 grams naturally occurring in Earth's crust at any given time.
93
Np
(237)
Neptunium
Neptunium is a chemical element with the symbol Np and atomic number 93. A radioactive actinide metal, neptunium is the first transuranic element. Its position in the periodic table just after uranium, named after the planet Uranus, led to it being named after Neptune, the next planet beyond Uranus.
62
Sm
150.36
Samarium
Samarium is a chemical element with the symbol Sm and atomic number 62. It is a moderately hard silvery metal that slowly oxidizes in air. Being a typical member of the lanthanide series, samarium usually assumes the oxidation state +3.
94
Pu
(244)
Plutonium
Plutonium is a radioactive chemical element with the symbol Pu and atomic number 94. It is an actinide metal of silvery-gray appearance that tarnishes when exposed to air, and forms a dull coating when oxidized. The element normally exhibits six allotropes and four oxidation states.
63
Eu
151.96
Europium
Europium is a chemical element with the symbol Eu and atomic number 63. Europium is the most reactive lanthanide by far, having to be stored under an inert fluid to protect it from atmospheric oxygen or moisture.
95
Am
(243)
Americium
Americium is a synthetic radioactive chemical element with the symbol Am and atomic number 95. It is a transuranic member of the actinide series, in the periodic table located under the lanthanide element europium, and thus by analogy was named after the Americas.
64
Gd
157.25
Gadolinium
Gadolinium is a chemical element with the symbol Gd and atomic number 64. Gadolinium is silvery-white metal when oxidation is removed. It is only slightly malleable and is a ductile rare-earth element. Gadolinium reacts with atmospheric oxygen or moisture slowly to form a black coating.
96
Cm
(247)
Curium
Curium is a transuranic radioactive chemical element with the symbol Cm and atomic number 96. This element of the actinide series was named after Marie and Pierre Curie – both were known for their research on radioactivity.
95
Tb
158.93
Terbium
Terbium is a chemical element with the symbol Tb and atomic number 65. It is a silvery-white, rare earth metal that is malleable, ductile, and soft enough to be cut with a knife. The ninth member of the lanthanide series, terbium is a fairly electropositive metal that reacts with water, evolving hydrogen gas.
97
Bk
(247)
Berkelium
Berkelium is a transuranic radioactive chemical element with the symbol Bk and atomic number 97. It is a member of the actinide and transuranium element series. It is named after the city of Berkeley, California, the location of the Lawrence Berkeley National Laboratory where it was discovered in December 1949.
66
Dy
162.50
Dysprosium
Dysprosium is a chemical element with the symbol Dy and atomic number 66. It is a rare earth element with a metallic silver luster. Dysprosium is never found in nature as a free element, though it is found in various minerals, such as xenotime. Naturally occurring dysprosium is composed of seven isotopes, the most abundant of which is Dy.
98
Cf
(251)
Californium
Californium is a radioactive chemical element with the symbol Cf and atomic number 98. The element was first synthesized in 1950 at the Lawrence Berkeley National Laboratory, by bombarding curium with alpha particles.
67
Ho
164.93
Holmium
Holmium is a chemical element with the symbol Ho and atomic number 67. Part of the lanthanide series, holmium is a rare-earth element. Holmium was discovered by Swedish chemist Per Theodor Cleve.
99
Es
(252)
Einsteinium
Einsteinium is a synthetic element with the symbol Es and atomic number 99. As a member of the actinide series, it is the seventh transuranic element.
68
Er
167.26
Erbium
Erbium is a chemical element with the symbol Er and atomic number 68. A silvery-white solid metal when artificially isolated, natural erbium is always found in chemical combination with other elements.
100
Fm
(257)
Fermium
Fermium is a synthetic element with the symbol Fm and atomic number 100. It is an actinide and the heaviest element that can be formed by neutron bombardment of lighter elements, and hence the last element that can be prepared in macroscopic quantities, although pure fermium metal has not yet been prepared.
69
Tm
168.93
Thulium
Thulium is a chemical element with the symbol Tm and atomic number 69. It is the thirteenth and third-last element in the lanthanide series. Like the other lanthanides, the most common oxidation state is +3, seen in its oxide, halides and other compounds; because it occurs so late in the series.
101
Md
(258)
Mendelevium
Mendelevium is a synthetic element with the symbol Md and atomic number 101. A metallic radioactive transuranic element in the actinide series, it is the first element that currently cannot be produced in macroscopic quantities through neutron bombardment of lighter elements.
70
Yb
173.05
Ytterbium
Ytterbium is a chemical element with the symbol Yb and atomic number 70. It is the fourteenth and penultimate element in the lanthanide series, which is the basis of the relative stability of its +2 oxidation state.
102
No
(259)
Nobelium
Nobelium is a synthetic chemical element with the symbol No and atomic number 102. It is named in honor of Alfred Nobel, the inventor of dynamite and benefactor of science. A radioactive metal, it is the tenth transuranic element and is the penultimate member of the actinide series.
71
Lu
174.97
Lutetium
Lutetium is a chemical element with the symbol Lu and atomic number 71. It is a silvery white metal, which resists corrosion in dry air, but not in moist air. Lutetium is the last element in the lanthanide series, and it is traditionally counted among the rare earths.
103
Lr
(266)
Lawrencium
Lawrencium is a synthetic chemical element with the symbol Lr (formerly Lw) and atomic number 103. It is named in honor of Ernest Lawrence, inventor of the cyclotron, a device that was used to discover many artificial radioactive elements.