1

Hhydrogen

[1.007; 1.009]

1 18

3

Lilithium

[6.938; 6.997]

4

Beberyllium

9.012

11

Nasodium

22.99

12

Mgmagnesium

24.31

19

Kpotassium

39.10

20

Cacalcium

40.08

37

Rbrubidium

85.47

38

Srstrontium

87.62

38

Srstrontium

87.62

55

Cscaesium

132.9

55

Cscaesium

132.9

56

Babarium

137.3

87

Frfrancium

88

Raradium

5

Bboron

[10.80; 10.83]

13

Alaluminium

26.98

31

Gagallium

69.72

49

Inindium114.8

81

Tlthallium

[204.3; 204.4]

6

Ccarbon

[12.00; 12.02]

14

Sisilicon

[28.08; 28.09]

32

Gegermanium

72.63

50

Sntin

118.7

82

Pblead207.2

7

Nnitrogen

[14.00; 14.01]

15

Pphosphorus

30.97

33

Asarsenic

74.92

51

Sbantimony

121.8

83

Bibismuth

209.0

8

Ooxygen

[15.99; 16.00]

16

Ssulfur

[32.05; 32.08]

34

Seselenium78.96(3)

52

Tetellurium

127.6

84

Popolonium

9

Ffluorine

19.00

17

Clchlorine

[35.44; 35.46]

35

Brbromine

79.90

53

Iiodine126.9

85

Atastatine

10

Neneon20.18

2

Hehelium4.003

18

Arargon39.95

36

Krkrypton

83.80

54

Xexenon131.3

86

Rnradon

22

Tititanium

47.87

22

Tititanium

47.87

40

Zrzirconium

91.22

72

Hfhafnium

178.5

104

Rfrutherfordium

23

Vvanadium

50.94

41

Nbniobium

92.91

73

Tatantalum

180.9

105

Dbdubnium

24

Crchromium

52.00

24

Crchromium

52.00

42

Momolybdenum

95.96(2)

74

Wtungsten

183.8

106

Sgseaborgium

25

Mnmanganese

54.94

43

Tctechnetium

75

Rerhenium

186.2

107

Bhbohrium

26

Feiron55.85

44

Ruruthenium

101.1

76

Ososmium

190.2

108

Hshassium

27

Cocobalt58.93

45

Rhrhodium

102.9

77

Iriridium192.2

109

Mtmeitnerium

28

Ninickel58.69

46

Pdpalladium

106.4

78

Ptplatinum

195.1

110

Dsdarmstadtium

29

Cucopper

63.55

47

Agsilver107.9

79

Augold197.0

30

Znzinc

65.38(2)

48

Cdcadmium

112.4

80

Hgmercury

200.6

111

Rgroentgenium

112

Cncopernicium

57

Lalanthanum

138.9

89

Acactinium

58

Cecerium140.1

90

Ththorium

232.0

59

Prpraseodymium

140.9

91

Paprotactinium

231.0

60

Ndneodymium

144.2

92

Uuranium

238.0

61

Pmpromethium

93

Npneptunium

62

Smsamarium

150.4

94

Puplutonium

63

Eueuropium

152.0

95

Amamericium

64

Gdgadolinium

157.3

96

Cmcurium

65

Tbterbium

158.9

97

Bkberkelium

66

Dydysprosium

162.5

98

Cfcalifornium

67

Hoholmium

164.9

99

Eseinsteinium

68

Ererbium

167.3

100

Fmfermium

69

Tmthulium

168.9

101

Mdmendelevium

70

Ybytterbium

173.1

102

Nonobelium

71

Lulutetium

175.0

103

Lrlawrencium

21

Scscandium

44.96

39

Yyttrium88.91

57-71

lanthanoids

89-103

actinoids

atomic number

Symbol

standard atomic weight

2 13 14 15 16 17 Key:

3 4 5 6 7 8 9 10 11 12

name

For updates to this table, see iupac.org/reports/periodic_table/. This version is dated 21 January 2011.Copyright © 2011 IUPAC, the International Union of Pure and Applied Chemistry.

Notes- IUPAC 2009 Standard atomic weights abridged to four significant digits (Table 4 published in Pure Appl. Chem. 83, 359-396 (2011); doi:10.1351/PAC-REP-10-09-14). The uncertainty in the last digit of the standard atomic weight value is listed in parentheses following the value. In the absence of parentheses, the uncertainty is one in that last digit. An interval in square brackets provides the lower and upper bounds of the standard atomic weight for that element. No values are listed for elements with no stable isotopes. See PAC for more details.

- “Aluminum” and “cesium” are commonly used alternative spellings for “aluminium” and “caesium.”

IUPAC Periodic Table of the Elements