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College Physics 2e

A | Atomic Masses

College Physics 2eA | Atomic Masses
Atomic Number, Z Name Atomic Mass Number, A Symbol Atomic Mass (u) Percent Abundance or Decay Mode Half-life, t1/2
0 neutron 1 n n 1.008 665 β − β − 10.37 min
1 Hydrogen 1 1 H 1 H 1.007 825 99.985%
Deuterium 2 2 H or D 2 H or D 2.014 102 0.015%
Tritium 3 3 H or T 3 H or T 3.016 050 β − β − 12.33 y
2 Helium 3 3 He 3 He 3.016 030 1 . 38 × 10 − 4 % 1 . 38 × 10 − 4 %
4 4 He 4 He 4.002 603 ≈100% ≈100%
3 Lithium 6 6 Li 6 Li 6.015 121 7.5%
7 7 Li 7 Li 7.016 003 92.5%
4 Beryllium 7 7 Be 7 Be 7.016 928 EC 53.29 d
9 9 Be 9 Be 9.012 182 100%
5 Boron 10 10 B 10 B 10.012 937 19.9%
11 11 B 11 B 11.009 305 80.1%
6 Carbon 11 11 C 11 C 11.011 432 EC, β + β +
12 12 C 12 C 12.000 000 98.90%
13 13 C 13 C 13.003 355 1.10%
14 14 C 14 C 14.003 241 β − β − 5730 y
7 Nitrogen 13 13 N 13 N 13.005 738 β + β + 9.96 min
14 14 N 14 N 14.003 074 99.63%
15 15 N 15 N 15.000 108 0.37%
8 Oxygen 15 15 O 15 O 15.003 065 EC, β + β + 122 s
16 16 O 16 O 15.994 915 99.76%
18 18 O 18 O 17.999 160 0.200%
9 Fluorine 18 18 F 18 F 18.000 937 EC, β + β + 1.83 h
19 19 F 19 F 18.998 403 100%
10 Neon 20 20 Ne 20 Ne 19.992 435 90.51%
22 22 Ne 22 Ne 21.991 383 9.22%
11 Sodium 22 22 Na 22 Na 21.994 434 β + β + 2.602 y
23 23 Na 23 Na 22.989 767 100%
24 24 Na 24 Na 23.990 961 β − β − 14.96 h
12 Magnesium 24 24 Mg 24 Mg 23.985 042 78.99%
13 Aluminum 27 27 Al 27 Al 26.981 539 100%
14 Silicon 28 28 Si 28 Si 27.976 927 92.23% 2.62h
31 31 Si 31 Si 30.975 362 β − β −
15 Phosphorus 31 31 P 31 P 30.973 762 100%
32 32 P 32 P 31.973 907 β − β − 14.28 d
16 Sulfur 32 32 S 32 S 31.972 070 95.02%
35 35 S 35 S 34.969 031 β − β − 87.4 d
17 Chlorine 35 35 Cl 35 Cl 34.968 852 75.77%
37 37 Cl 37 Cl 36.965 903 24.23%
18 Argon 40 40 Ar 40 Ar 39.962 384 99.60%
19 Potassium 39 39 K 39 K 38.963 707 93.26%
40 40 K 40 K 39.963 999 0.0117%, EC, β−β− 1 . 28 × 10 9 y 1 . 28 × 10 9 y
20 Calcium 40 40 Ca 40 Ca 39.962 591 96.94%
21 Scandium 45 45 Sc 45 Sc 44.955 910 100%
22 Titanium 48 48 Ti 48 Ti 47.947 947 73.8%
23 Vanadium 51 51 V 51 V 50.943 962 99.75%
24 Chromium 52 52 Cr 52 Cr 51.940 509 83.79%
25 Manganese 55 55 Mn 55 Mn 54.938 047 100%
26 Iron 56 56 Fe 56 Fe 55.934 939 91.72%
27 Cobalt 59 59 Co 59 Co 58.933 198 100%
60 60 Co 60 Co 59.933 819 β − β − 5.271 y
28 Nickel 58 58 Ni 58 Ni 57.935 346 68.27%
60 60 Ni 60 Ni 59.930 788 26.10%
29 Copper 63 63 Cu 63 Cu 62.939 598 69.17%
65 65 Cu 65 Cu 64.927 793 30.83%
30 Zinc 64 64 Zn 64 Zn 63.929 145 48.6%
66 66 Zn 66 Zn 65.926 034 27.9%
31 Gallium 69 69 Ga 69 Ga 68.925 580 60.1%
32 Germanium 72 72 Ge 72 Ge 71.922 079 27.4%
74 74 Ge 74 Ge 73.921 177 36.5%
33 Arsenic 75 75 As 75 As 74.921 594 100%
34 Selenium 80 80 Se 80 Se 79.916 520 49.7%
35 Bromine 79 79 Br 79 Br 78.918 336 50.69%
36 Krypton 84 84 Kr 84 Kr 83.911 507 57.0%
37 Rubidium 85 85 Rb 85 Rb 84.911 794 72.17%
38 Strontium 86 86 Sr 86 Sr 85.909 267 9.86%
88 88 Sr 88 Sr 87.905 619 82.58%
90 90 Sr 90 Sr 89.907 738 β−β− ­ 28.8 y
39 Yttrium 89 89 Y 89 Y 88.905 849 100%
90 90 Y 90 Y 89.907 152 β−β− ­ 64.1 h
40 Zirconium 90 90 Zr 90 Zr 89.904 703 51.45%
41 Niobium 93 93 Nb 93 Nb 92.906 377 100%
42 Molybdenum 98 98 Mo 98 Mo 97.905 406 24.13%
43 Technetium 98 98 Tc 98 Tc 97.907 215 β−β− ­ 4 . 2 × 10 6 y 4 . 2 × 10 6 y
44 Ruthenium 102 102 Ru 102 Ru 101.904 348 31.6%
45 Rhodium 103 103 Rh 103 Rh 102.905 500 100%
46 Palladium 106 106 Pd 106 Pd 105.903 478 27.33%
47 Silver 107 107 Ag 107 Ag 106.905 092 51.84%
109 109 Ag 109 Ag 108.904 757 48.16%
48 Cadmium 114 114 Cd 114 Cd 113.903 357 28.73%
49 Indium 115 115 In 115 In 114.903 880 95.7%, β−β− ­ 4 . 4 × 10 14 y 4 . 4 × 10 14 y
50 Tin 120 120 Sn 120 Sn 119.902 200 32.59%
51 Antimony 121 121 Sb 121 Sb 120.903 821 57.3%
52 Tellurium 130 130 Te 130 Te 129.906 229 33.8%, β−β− ­ 2 . 5 × 10 21 y 2 . 5 × 10 21 y
53 Iodine 127 127 I 127 I 126.904 473 100%
131 131 I 131 I 130.906 114 β−β− ­ 8.040 d
54 Xenon 132 132 Xe 132 Xe 131.904 144 26.9%
136 136 Xe 136 Xe 135.907 214 8.9%
55 Cesium 133 133 Cs 133 Cs 132.905 429 100%
134 134 Cs 134 Cs 133.906 696 EC, β−β− ­ 2.06 y
56 Barium 137 137 Ba 137 Ba 136.905 812 11.23%
138 138 Ba 138 Ba 137.905 232 71.70%
57 Lanthanum 139 139 La 139 La 138.906 346 99.91%
58 Cerium 140 140 Ce 140 Ce 139.905 433 88.48%
59 Praseodymium 141 141 Pr 141 Pr 140.907 647 100%
60 Neodymium 142 142 Nd 142 Nd 141.907 719 27.13%
61 Promethium 145 145 Pm 145 Pm 144.912 743 EC, αα 17.7 y
62 Samarium 152 152 Sm 152 Sm 151.919 729 26.7%
63 Europium 153 153 Eu 153 Eu 152.921 225 52.2%
64 Gadolinium 158 158 Gd 158 Gd 157.924 099 24.84%
65 Terbium 159 159 Tb 159 Tb 158.925 342 100%
66 Dysprosium 164 164 Dy 164 Dy 163.929 171 28.2%
67 Holmium 165 165 Ho 165 Ho 164.930 319 100%
68 Erbium 166 166 Er 166 Er 165.930 290 33.6%
69 Thulium 169 169 Tm 169 Tm 168.934 212 100%
70 Ytterbium 174 174 Yb 174 Yb 173.938 859 31.8%
71 Lutecium 175 175 Lu 175 Lu 174.940 770 97.41%
72 Hafnium 180 180 Hf 180 Hf 179.946 545 35.10%
73 Tantalum 181 181 Ta 181 Ta 180.947 992 99.98%
74 Tungsten 184 184 W 184 W 183.950 928 30.67%
75 Rhenium 187 187 Re 187 Re 186.955 744 62.6%, β−β− 4 . 6 × 10 10 y 4 . 6 × 10 10 y
76 Osmium 191 191 Os 191 Os 190.960 920 β−β− ­ 15.4 d
192 192 Os 192 Os 191.961 467 41.0%
77 Iridium 191 191 Ir 191 Ir 190.960 584 37.3%
193 193 Ir 193 Ir 192.962 917 62.7%
78 Platinum 195 195 Pt 195 Pt 194.964 766 33.8%
79 Gold 197 197 Au 197 Au 196.966 543 100%
198 198 Au 198 Au 197.968 217 β−β− ­ 2.696 d
80 Mercury 199 199 Hg 199 Hg 198.968 253 16.87%
202 202 Hg 202 Hg 201.970 617 29.86%
81 Thallium 205 205 Tl 205 Tl 204.974 401 70.48%
82 Lead 206 206 Pb 206 Pb 205.974 440 24.1%
207 207 Pb 207 Pb 206.975 872 22.1%
208 208 Pb 208 Pb 207.976 627 52.4%
210 210 Pb 210 Pb 209.984 163 α,β−α,β− ­ 22.3 y
211 211 Pb 211 Pb 210.988 735 β−β− ­ 36.1 min
212 212 Pb 212 Pb 211.991 871 β−β− ­ 10.64 h
83 Bismuth 209 209 Bi 209 Bi 208.980 374 100%
211 211 Bi 211 Bi 210.987 255 α , β − α , β − 2.14 min
84 Polonium 210 210 Po 210 Po 209.982 848 α α 138.38 d
85 Astatine 218 218 At 218 At 218.008 684 α , β − α , β − 1.6 s
86 Radon 222 222 Rn 222 Rn 222.017 570 α α 3.82 d
87 Francium 223 223 Fr 223 Fr 223.019 733 α , β − α , β − 21.8 min
88 Radium 226 226 Ra 226 Ra 226.025 402 α α 1 . 60 × 10 3 y 1 . 60 × 10 3 y
89 Actinium 227 227 Ac 227 Ac 227.027 750 α , β − α , β − 21.8 y
90 Thorium 228 228 Th 228 Th 228.028 715 α α 1.91 y
232 232 Th 232 Th 232.038 054 100%, αα 1 . 41 × 10 10 y 1 . 41 × 10 10 y
91 Protactinium 231 231 Pa 231 Pa 231.035 880 α α 3 . 28 × 10 4 y 3 . 28 × 10 4 y
92 Uranium 233 233 U 233 U 233.039 628 α α 1 . 59 × 10 3 y 1 . 59 × 10 3 y
235 235 U 235 U 235.043 924 0.720%, αα 7 . 04 × 10 8 y 7 . 04 × 10 8 y
236 236 U 236 U 236.045 562 α α 2 . 34 × 10 7 y 2 . 34 × 10 7 y
238 238 U 238 U 238.050 784 99.2745%, αα 4 . 47 × 10 9 y 4 . 47 × 10 9 y
239 239 U 239 U 239.054 289 β−β− ­ 23.5 min
93 Neptunium 239 239 Np 239 Np 239.052 933 β−β− ­ 2.355 d
94 Plutonium 239 239 Pu 239 Pu 239.052 157 α α 2 . 41 × 10 4 y 2 . 41 × 10 4 y
95 Americium 243 243 Am 243 Am 243.061 375 α,α, fission 7 . 37 × 10 3 y 7 . 37 × 10 3 y
96 Curium 245 245 Cm 245 Cm 245.065 483 α α 8 . 50 × 10 3 y 8 . 50 × 10 3 y
97 Berkelium 247 247 Bk 247 Bk 247.070 300 α α 1 . 38 × 10 3 y 1 . 38 × 10 3 y
98 Californium 249 249 Cf 249 Cf 249.074 844 α α 351 y
99 Einsteinium 254 254 Es 254 Es 254.088 019 α,β−α,β− ­ 276 d
100 Fermium 253 253 Fm 253 Fm 253.085 173 EC, αα 3.00 d
101 Mendelevium 255 255 Md 255 Md 255.091 081 EC, αα 27 min
102 Nobelium 255 255 No 255 No 255.093 260 EC, αα 3.1 min
103 Lawrencium 257 257 Lr 257 Lr 257.099 480 EC, αα 0.646 s
104 Rutherfordium 261 261 Rf 261 Rf 261.108 690 α α 1.08 min
105 Dubnium 262 262 Db 262 Db 262.113 760 α,α, fission 34 s
106 Seaborgium 263 263 Sg 263 Sg 263.11 86 α,α, fission 0.8 s
107 Bohrium 262 262 Bh 262 Bh 262.123 1 α α 0.102 s
108 Hassium 264 264 Hs 264 Hs 264.128 5 α α 0.08 ms
109 Meitnerium 266 266 Mt 266 Mt 266.137 8 α α 3.4 ms
Table A1 Atomic Masses
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