Periodic Table of the Elements
1
18
Hydrogen
Helium
1
H
1.01
2.1
Lithium
3
Li
6.94
1.0
Beryllium
4
Be
1.5
Na
Mg
12
22.99
24.31
Potassium
K
0.9
19
39.10
0.8
Rubidium
37
Rb
All average masses are to
be treated as measured
quantities, and subject to
significant figure rules.
9.01
Magnesium
11
Average relative masses
are rounded to two
decimal places.
2
Sodium
Element
Name
3
4
5
Calcium
Scandium
Titanium
Vanadium
Ca
Sc
Ti
V
1.2
20
21
22
40.08
44.96
47.88
50.94
Strontium
Yttrium
Zirconium
Niobium
1.0
1.3
38
39
Y
Sr
1.5
40
Zr
1.6
41
Nb
Hg
7
Chromium Manganese
24
25
Cr
52.00
1.6
Mn
1.9
54.94
1.5
42
Mo
Ru
Tc
92.91
95.94
(98)
Cesium
Barium
Lutetium
Hafnium
Tantalum
Tungsten
Rhenium
Osmium
Cs
Ba
Lu
Hf
Ta
W
Re
Os
0.8
55
1.0
56
132.91
137.33
Francium
Radium
Fr
Ra
0.7
87
(223)
0.7
1.2
57-70
*
72
1.6
73
174.97 178.49 180.95
0.9
88
71
1.4
1.1
Lawrencium Rutherfordium
89-102
**
(226)
0.9
*lanthanides
103
104
Lr
(262)
(261)
Cerium
La
Ce
58
74
1.9
75
76
1.7
2.2
1.9
Hassium
Db
Sg
Bh
Hs
106
(266)
107
(264)
---
---
108
(269)
---
60
Pr
Nd
61
Pm
62
Sm
138.91 140.12 140.91
144.24
(145)
Actinium
Thorium
Protactinium
Uranium
Neptunium
Plutonium
Ac
Th
Pa
U
Np
Pu
89
(227)
1.1
1.1
90
1.1
91
232.04 231.04
1.3
1.5
1.1
92
238.03
1.4
1.1
93
(237)
1.4
94
(244)
1.3
Si
1.8
46
Pd
Silver
Cadmium
Indium
Tin
Cd
In
Sn
1.6
48
1.6
49
Thallium
Ir
Pt
Au
Hg
Tl
2.2
195.08
2.2
196.97
2.4
1.7
110
Mt
(268)
(271)
--Europium
63
Eu
Rg
(272)
---
Gadolinium
64
81
1.9
Gd
65
Tb
(277)
Uut
(284)
Dysprosium Holmium
66
Dy
67
Ho
(243)
1.3
(247)
1.3
(247)
1.3
99
(251)
1.3
Es
(252)
1.3
Antimony
Tellurium
Iodine
Xenon
Sb
52
Te
53
I
3.0
54
Xe
Po
At
Rn
1.9
83
1.8
Flerovium
114
Fl
(289)
208.98
1.9
Erbium
68
Er
1.2
Fermium
100
Fm
(257)
1.3
2.1
84
(209)
2.0
2.5
85
(210)
2.2
2.6
86
(222)
2.4
Ununpentium Livermorium Ununseptium Ununoctium
115
116
(288)
(293)
Uup
Lv
---
---
Bk
98
83.80
2.8
Bi
82
Cm
Cf
79.90
2.4
Pb
Am
97
78.96
2.0
Radon
Californium Einsteinium
96
74.92
Astatine
Berkelium
95
36
Polonium
Curium
1.2
35
---
Bismuth
1.8
Americium
1.2
34
3.0
Lead
162.50 164.93 167.26
1.1
33
2.5
131.29
---
---
2.1
126.90
158.93
1.2
18
127.60
157.25
1.1
Ar
17
121.76
1.8
113
Cn
--Terbium
Cl
51
200.59 204.38 207.20
112
111
Ds
50
1.7
Meitnerium Darmstadtium Roegentium Copernicium Ununtrium
109
1.8
112.41 114.82 118.71
80
79
S
16
Kr
Mercury
78
P
15
---
Br
Gold
77
Argon
4.0
Se
72.61
1.9
Chlorine
3.5
As
32
69.72
Ag
Sulfur
3.0
Ge
31
65.39
47
Phosphorus
Ga
30
1.8
63.55
1.9
20.18
Zn
Platinum
2.2
14
Ne
19.00
Krypton
Iridium
2.2
2.5
F
16.00
14.01
Bromine
1.5
107.87
150.36 151.97
1.2
Al
106.42
---
Praseodymium Neodymium Promethium Samarium
59
Palladium
183.84 186.21 190.23 192.22
Bohrium
(262)
Rhodium
2.2
Seaborgium
105
58.69
101.07 102.91
Dubnium
---
Lanthanum
1.1
**actinides
Rf
---
57
1.5
1.3
1.8
58.93
Rh
91.22
Silicon
O
10
Selenium
Cu
88.91
Aluminum
N
9
Arsenic
Ni
87.62
12.01
8
Germanium
Co
29
C
10.81
7
---
Gallium
Fe
28
6
Neon
Zinc
Copper
85.47
Fluorine
39.95
Nickel
45
Oxygen
35.45
Cobalt
44
43
Nitrogen
32.07
Iron
Molybdenum Technetium Ruthenium
Carbon
30.97
12
1.8
Boron
28.09
11
1.8
17
26.98
10
55.85
16
13
9
27
15
2.0
8
26
14
B
Average
Mass
4.00
13
5
200.59
Electronegativity
He
Atomic
Number
80
Symbol
6
23
2
Mercury
Thulium
69
Tm
168.93
1.3
--Ytterbium
70
Yb
173.04
1.1
Mendelevium Nobelium
101
Md
(258)
1.3
102
No
(259)
1.3
117
Uus
(294)
---
118
Uuo
(294)
---