1
H
hydrogen
1.007 94(7)
1 18
3
Li
lithium
6.941(2)
4
Be
beryllium
9.012 182(3)
11
Na
sodium
22.989 769 28(2)
12
Mg
magnesium
24.3050(6)
19
K
potassium
39.0983(1)
20
Ca
calcium
40.078(4)
37
Rb
rubidium
85.4678(3)
38
Sr
strontium
87.62(1)
38
Sr
strontium
87.62(1)
55
Cs
caesium
132.905 4519(2)
55
Cs
caesium
132.905 4519(2)
56
Ba
barium
137.327(7)
87
Fr
francium
[223]
88
Ra
radium
[226]
5
B
boron
10.811(7)
13
Al
aluminium
26.981 5386(8)
31
Ga
gallium
69.723(1)
49
In
indium
114.818(3)
81
Tl
thallium
204.3833(2)
6
C
carbon
12.0107(8)
14
Si
silicon
28.0855(3)
32
Ge
germanium
72.64(1)
50
Sn
tin
118.710(7)
82
Pb
lead
207.2(1)
7
N
nitrogen
14.0067(2)
15
P
phosphorus
30.973 762(2)
33
As
arsenic
74.921 60(2)
51
Sb
antimony
121.760(1)
83
Bi
bismuth
208.980 40(1)
8
O
oxygen
15.9994(3)
16
S
sulfur
32.065(5)
34
Se
selenium
78.96(3)
52
Te
tellurium
127.60(3)
84
Po
polonium
[209]
9
F
fluorine
18.998 4032(5)
17
Cl
chlorine
35.453(2)
35
Br
bromine
79.904(1)
53
I
iodine
126.904 47(3)
85
At
astatine
[210]
10
Ne
neon
20.1797(6)
2
He
helium
4.002 602(2)
18
Ar
argon
39.948(1)
36
Kr
krypton
83.798(2)
54
Xe
xenon
131.293(6)
86
Rn
radon
[222]
22
Ti
titanium
47.867(1)
22
Ti
titanium
47.867(1)
40
Zr
zirconium
91.224(2)
72
Hf
hafnium
178.49(2)
104
Rf
rutherfordium
[261]
23
V
vanadium
50.9415(1)
41
Nb
niobium
92.906 38(2)
73
Ta
tantalum
180.947 88(2)
105
Db
dubnium
[262]
24
Cr
chromium
51.9961(6)
24
Cr
chromium
51.9961(6)
42
Mo
molybdenum
95.94(2)
74
W
tungsten
183.84(1)
106
Sg
seaborgium
[266]
25
Mn
manganese
54.938 045(5)
43
Tc
technetium
[98]
75
Re
rhenium
186.207(1)
107
Bh
bohrium
[264]
26
Fe
iron
55.845(2)
44
Ru
ruthenium
101.07(2)
76
Os
osmium
190.23(3)
108
Hs
hassium
[277]
27
Co
cobalt
58.933 195(5)
45
Rh
rhodium
102.905 50(2)
77
Ir
iridium
192.217(3)
109
Mt
meitnerium
[268]
28
Ni
nickel
58.6934(2)
46
Pd
palladium
106.42(1)
78
Pt
platinum
195.084(9)
110
Ds
darmstadtium
[271]
29
Cu
copper
63.546(3)
47
Ag
silver
107.8682(2)
79
Au
gold
196.966 569(4)
30
Zn
zinc
65.409(4)
48
Cd
cadmium
112.411(8)
80
Hg
mercury
200.59(2)
111
Rg
roentgenium
[272]
57
La
lanthanum
138.905 47(7)
89
Ac
actinium
[227]
58
Ce
cerium
140.116(1)
90
Th
thorium
232.038 06(2)
59
Pr
praseodymium
140.907 65(2)
91
Pa
protactinium
231.035 88(2)
60
Nd
neodymium
144.242(3)
92
U
uranium
238.028 91(3)
61
Pm
promethium
[145]
93
Np
neptunium
[237]
62
Sm
samarium
150.36(2)
94
Pu
plutonium
[244]
63
Eu
europium
151.964(1)
95
Am
americium
[243]
64
Gd
gadolinium
157.25(3)
96
Cm
curium
[247]
65
Tb
terbium
158.925 35(2)
97
Bk
berkelium
[247]
66
Dy
dysprosium
162.500(1)
98
Cf
californium
[251]
67
Ho
holmium
164.930 32(2)
99
Es
einsteinium
[252]
68
Er
erbium
167.259(3)
100
Fm
fermium
[257]
69
Tm
thulium
168.934 21(2)
101
Md
mendelevium
[258]
70
Yb
ytterbium
173.04(3)
102
No
nobelium
[259]
71
Lu
lutetium
174.967(1)
103
Lr
lawrencium
[262]
21
Sc
scandium
44.955 912(6)
39
Y
yttrium
88.905 85(2)
57-71
lanthanoids
89-103
actinoids
atomic number
Symbol
standard atomic weight
2 13 14 15 16 17Key:
3 4 5 6 7 8 9 10 11 12
name
Notes
- "Aluminum" and "cesium" are commonly used alternative spellings for "aluminium" and "caesium."
- IUPAC 2005 standard atomic weights (mean relative atomic masses) as approved at the 43rd IUPAC General Assembly in Beijing, China in August 2005 are listed with uncertainties in the last figure in parentheses [M. E. Wieser, Pure Appl. Chem., in press].
These values correspond to current best knowledge of the elements in natural terrestrial sources. For elements that have no stable or long-lived nuclides, the mass number of the nuclide with the longest confirmed half-life is listed between square brackets.
- Elements with atomic numbers 112 and above have been reported but not fully authenticated.
Copyright  2005 IUPAC, the International Union of Pure and Applied Chemistry. For updates to this table, see http://www.iupac.org/reports/periodic_table/. This version is dated 3 October 2005.
IUPAC Periodic Table of the Elements
energy E molar energy
Em
wavenumber

J eV Eh kJ/mol cm-1
1 aJ 10-18
6.241 509 0.229 3713 602.2142 50 341.17
1 eV 1.602 177x10-19
1 3.674 932x10-2
96.485 34 8 065.544
1 Eh 4.359 744 x10-18
27.211 38 1 2625.500 219 474.6
1 kJ/mol 1.660 539 x10-21
1.036 427 x10-2
3.808 799 x10-4
1 83.593 47
1 cm-1
1.986 446 x10-23
1.239 842 x10-4
4.556 335 x10-6
11.962 66 x10-3
1
General Data and Fundamental Constants
Source: The National Institute of Standards and Technology (NIST) reference on Constants, Units, and Uncertainties (2002 values)
<http://physics.nist.gov/cuu/constants>.
Speed of light in vacuum c0 299 792 458 m s-1
(defined)
Elementary charge e 1.602 176 53(14) x 10-19
C
Boltzmann constant k, kB 1.380 650 5(24) x 10-23
J K-1
Planck constant h
h = h/2
6.626 069 3(11) x 10-34
J s
1.054 571 68(18) x 10-34
J s
Avogadro constant L, NA 6.022 141 5(10) x 1023
mol-1
Gas constant R 8.314 472 (15) J K-1
mol-1
Faraday constant F 9.648 533 83(83) x 104
C mol-1
Atomic mass constant
(dalton, or unified atomic mass unit,
mu = Da = u 1.660 538 86(28) x 10-27
kg
Electron rest mass me 9.109 382 6(16) x 10-31
kg
Proton rest mass mp 1.672 621 71(29) x 10-27
kg
Neutron rest mass mn 1.674 927 28(29) x 10-27
kg
m(12
C)/12)
Fine structure constant  = 0 e2
c0 /2h 7.297 352 568(24) x 10-3
Second radiation constant c2 = hc0/k 1.438 775 2(25) x 10-2
m K
Stefan-Boltzmann constant  = 25
k4
/15h3
c0
2
5.670 400(40) x 10-8
W m-2
K-4
Bohr radius a0 = 4 0 h2
/ me e2 5.291 772 108(18) x 10-11
m
Hartree energy Eh = h2
/ me a0
2
4.359 744 17(75) x 10-18
J
Rydberg constant R = Eh /2hc0 1.097 373 156 852 5(73) x 107
m-1
Standard acceleration of free fall gn 9.806 65 m s-2
(defined)
Gravitational constant G 6.674 2(10) x 10-11
m3
kg-1
s-2
Zero of Celsius scale 273.15 K (defined)
Molar volume of ideal gas,
p = 1 bar and T = 273.15 K
22.710 981 (40) L mol-1
Standard atmosphere 101 325 Pa (defined)
RT at 298.15 K 2.4790 kJ mol-1
Pa atm Torr
1 Pa = 1 9.869 23 x 10-6
7.500 62 x 10-3
1 atm = 101 325 1 760
1 Torr = 133.322 1.315 79 x 10-3
1
PRESSURE CONVERSION FACTORS
Example of the use of this table: 1 eV `corresponds to' or `is equivalent to' 96.485 34 kJ/mol
Note: 1 cal = 4.184 J
ENERGY CONVERSION FACTORS
Example of the use of this table: 1 atm = 101 325 Pa
Notes: 1 mmHg = 1 Torr ; 1 bar = 105
Pa
~
Permeability of vacuum
(or magnetic constant)
0 4 x 10-7
H m-1
(defined)
Permittivity of vacuum
(or electric constant)
0 = 1/0 c0
2 8.854 187 816... x 10-12
F m-1
Bohr magneton B = e h /2me 9.274 009 49(80) x 10-24
J T-1
Nuclear magneton N = (me /mp) B 5.050 783 43(43) x 10-27
J T-1
Landé g-factor for free electron ge 2.002 319 304 371 8(75)
Note: H m-1
= N A-2
= N s2
C-2
Note: F m-1
= C2
J-1
m-1