Atomic Numbers & Relative Atomic Masses of Elements


ATOMIC NUMBER NAME SYMBOL RELATIVE ATOMIC MASS
1 Hydrogen H 1.00794
2 Helium He 4.002602
3 Lithium Li 6.941
4 Beryllium Be 9.012182
5 Boron B 10.811
6 Carbon C 12.0107
7 Nitrogen N 14.0067
8 Oxygen O 15.9994
9 Fluorine F 18.9984032
10 Neon Ne 20.1797
11 Sodium Na 22.98976928
12 Magnesium MG 24.3050
13 Aluminium Al 26.9815386
14 Silicon Si 28.0855
15 Phosphorus P 30.973762
16 Sulfur S 32.065
17 Chlorine Cl 35.453
18 Argon Ar 39.948
19 Potassium K 39.0983
20 Calcium Ca 40.078
21 Scandium Sc 44.955912
22 Titanium Ti 47.867
23 Vanadium v 50.9415
24 Chromium Cr 51.9961
25 Manganese Mn 54.938045
26 Iron Fe 55.845
27 Cobalt Co 58.933195
28 Nickel Ni 58.6934
29 Copper (Cuprum) Cu 63.546
30 Zinc Zn 65.39
31 Gallium Ga 69.723
32 Germanium Ge 72.64
33 Arsenic As 74.92160
34 Selenium Se 78.96
35 Bromine Br 79.904
36 Krypton Kr 83.798
37 Rubidium Rb 85.4678
38 Strontium Sr 87.62
39 Yttrium Y 88.90585
40 Zirconium zr 91.224
41 Niobium Nb 92.906 38
42 Molybdenum Mo 95.94
43 Technetium Tc 97.9072*
44 Ruthenium Ru 101.07
45 Rhodium Rh 102.905 50
46 Palladium Pd 106.42
47 Silver Ag 107.8682
48 Cadmium Cd 112.411
49 Indium In 114.818
50 Tin Sn 118.710
51 Antimony Sb
52 Tellurium Te 127.60
53 Iodine I 126.904 47
54 Xenon Xe 131.293
55 Cesium Cs 132.9054519
56 Barium Ba 137.327
57 Lanthanum La 138.90547
58 Cerium Ce
59 Praseodymium Pr 140.90765
60 Neodymium Nd 144.242
61 Promethium Pm 144.9127
62 Samarium Sm 150.36
63 Europium Eu 151.964
64 Gadolinium Gd 157.25
65 Terbium Tb 158.92535
66 Dysprosium Dy 162.500
67 Holmium Ho 164.930 32
68 Erbium Er 167.259
69 Thulium Tm 168.93421
70 Ytterbium Yb 173.04
71 Lutetium Lu 174.967
72 Hafnium Hf 178.49
73 Tantalum Ta 180.94788
74 Tungsten (Wolfram) W 183.84
75 Rhenium Re 186.207
76 Osmium Os 190.23
77 Iridium Ir 192.217
78 Platinum Pt 195.084
79 Gold (Aurum) Au 196.966569
80 Mercury Hg 200.59
81 Thallium Tl 204.3833
82 Lead Pb 207.2
83 Bismuth Bi 208.98040
84 Polonium Po 208.9824*
85 Astatine At 209.9871*
86 Radon Rn 222.0176*
87 Francium Fr 223.0197*
88 Radium Ra 226.0254*
89 Actinium Ac 227.0277*
90 Thorium Th 232.03806*
91 Protactinium Pa 231.03588*
92 Uranium U 238.02891
93 Neptunium Np 237.0482*
94 Plutonium Pu 244.0642*
95 Americium Am 243.0614*
96 Curium Cm 247.0704*
97 Berkelium Bk 247.0703*
98 Californium Cf 251.0796*
99 Einsteinium Es 252.0830*
100 Fermium Fm 257.0951*
101 Mendelevium Md 258.0984*
102 Nobelium No 259.1010*
103 Lawrencium Lr 262.1097*
104 Rutherfordium Rf 261.1088*
105 Dubnium Db 262
106 Seaborgium Sg 266
107 Bohrium Bh 264
108 Hassium Hs 277
109 Meitnerium Mt 268
110 Darmstadtium Ds 271
111 Roentgenium Rg 272
112 Ununbium Uub 285
113 Ununtrium Uut 284
114 Ununquadium Uuq 289
115 Ununpentium Uup 288
116 Ununhexium Uuh 292
117 Ununseptium Uus -
118 Ununoctium Uuo 294
*Relative atomic mass of the isotope of the element with the longest known half-life is given.