Metals
Alkali metals
Alkaline-earth metals
Transition metals
Other metals
1
1
2
3
H
Group 1
Group 2
3
4
Li
Lithium
6.941
12
Mg
Period
K
Potassium
39.0983
37
5
6
Rb
Magnesium
24.3050
Group 3
20
Ca
Calcium
40.078
21
Sc
Scandium
44.955 910
38
Sr
39
Y
Group 4
22
Ti
Titanium
47.867
40
Zr
Atomic number
C
Symbol
Carbon
Name
12.0107
Average atomic mass
Group 5
23
V
Vanadium
50.9415
41
Nb
Group 6
24
Cr
Chromium
51.9961
42
Mo
Group 7
Group 8
25
26
Mn
Fe
Manganese
54.938 049
43
Tc
Iron
55.845
44
Ru
Group 9
27
Co
Cobalt
58.933 200
45
Rh
Strontium
87.62
Yttrium
88.905 85
Zirconium
91.224
Niobium
92.906 38
Molybdenum
95.94
Technetium
(98)
Ruthenium
101.07
Rhodium
102.905 50
55
56
57
72
73
74
75
76
77
Cs
Cesium
132.905 45
Fr
Francium
(223)
Ba
Barium
137.327
La
Lanthanum
138.9055
88
Ra
Radium
(226)
89
Ac
Actinium
(227)
Hf
Hafnium
178.49
104
Rf
Rutherfordium
(261)
Ta
Tantalum
180.9479
105
Db
Dubnium
(262)
W
Tungsten
183.84
106
Sg
Seaborgium
(263)
Re
Rhenium
186.207
107
Bh
Bohrium
(264)
Os
Osmium
190.23
108
Hs
Hassium
(265)†
Group 18
2
He
Nonmetals
Hydrogen
Semiconductors
Halogens
Noble gases
Other nonmetals
Rubidium
85.4678
87
7
Be
11
Sodium
22.989 770
Key:
Beryllium
9.012 182
Na
19
4
6
Hydrogen
1.007 94
Ir
Iridium
192.217
Group 10
28
Ni
Nickel
58.6934
Group 11
30
47
Ag
Silver
107.8682
78
79
Pt
Au
Platinum
195.078
Group 12
Zn
46
Gold
196.966 55
Group 15
Group 16
6
7
8
B
29
Pd
Palladium
106.42
Group 14
5
Boron
10.811
Cu
Copper
63.546
Group 13
48
Cd
Cadmium
112.411
80
Hg
Mercury
200.59
10
Ne
Neon
20.1797
14
15
16
17
18
P
S
Cl
Ar
Aluminum
26.981 538
Ga
Gallium
69.723
Silicon
28.0855
32
Ge
Germanium
72.61
49
50
In
Sn
Indium
114.818
Tin
118.710
81
82
Tl
Pb
Thallium
204.3833
Lead
207.2
110
111
112
114
Uun*
Uuu*
Uub*
Uuq*
Unununium
(272)†
9
F
Fluorine
18.998 4032
Si
109
Ununnilium
(269)†
O
Oxygen
15.9994
13
Mt
Meitnerium
(268)†
N
Nitrogen
14.006 74
Al
31
Zinc
65.39
C
Carbon
12.0107
Group 17
Helium
4.002 602
Ununbium
(277)†
Phosphorus
30.973 761
33
As
Arsenic
74.921 60
51
Sb
Antimony
121.760
83
Bi
Bismuth
208.980 38
Sulfur
32.066
Chlorine
35.4527
34
Se
Selenium
78.96
35
Br
Bromine
79.904
52
Te
Tellurium
127.60
53
I
Iodine
126.904 47
84
Po
Polonium
(209)
Argon
39.948
36
Kr
Krypton
83.80
54
Xe
Xenon
131.29
85
86
At
Rn
Astatine
(210)
Radon
(222)
Ununquadium
(285)†
A team at Lawrence Berkeley National reported the discovery of elements 116 and 118
in June 1999. The same team retracted the discovery in July 2001. The discovery of element 114 has been reported but not confirmed.
† Estimated from currently available
IUPAC data.
* The systematic names and symbols
for elements greater than 109 will
be used until the approval of trivial
names by IUPAC.
58
Ce
Cerium
140.116
90
Th
Thorium
232.0381
59
Pr
Praseodymium
140.907 65
91
Pa
Protactinium
231.035 88
60
Nd
Neodymium
144.24
92
U
Uranium
238.0289
61
Pm
Promethium
(145)
93
Np
Neptunium
(237)
62
63
64
65
66
67
68
69
70
71
Sm
Eu
Gd
Tb
Dy
Ho
Er
Tm
Yb
Lu
Samarium
150.36
94
Pu
Plutonium
(244)
Europium
151.964
Gadolinium
157.25
95
96
Am
Cm
Americium
(243)
Curium
(247)
Terbium
158.925 34
97
Bk
Berkelium
(247)
Dysprosium
162.50
98
Cf
Californium
(251)
Holmium
164.930 32
99
Es
Einsteinium
(252)
Erbium
167.26
100
Fm
Fermium
(257)
Thulium
168.934 21
Ytterbium
173.04
101
Md
Mendelevium
(258)
102
No
Nobelium
(259)
The atomic masses listed in this table reflect the precision of current measurements. (Values listed in
parentheses are those of the element’s most stable or most common isotope.) In calculations throughout
the text, however, atomic masses have been rounded to two places to the right of the decimal.
Lutetium
174.967
103
Lr
Lawrencium
(262)