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Alphabetic Listing of Elements

Exact Masses and Isotopic Abundances

Based on the Carbon 12 Standard

The following data was collected from a compilation of data from the CRC Handbook and other references. If any errors or corrections are notes please advise us and we will make the corrections.

Name         Symbol      Mass     Abund.    Symbol     Mass      Abund.   Symbol      Mass      Abund.
----------   -------  ----------  ------    -------  ----------  ------   -------  ----------   ------
Aluminum     Al(27)    26.981541  100.00                                                             
Antimony     Sb(121)  120.903824   57.30    Sb(123)  122.904222   42.70                               
Argon        Ar(36)    35.967546    0.34    Ar(38)    37.962732   0.063    Ar(40)    39.962383   99.60 
Arsenic      As(75)    74.921596  100.00                                                             
Barium       Ba(130)  129.906277    0.11    Ba(132)  131.905042    0.10    Ba(134)  133.904490    2.42 
             Ba(135)  134.905668    6.59    Ba(136)  135.904556    7.85    Ba(137)  136.905816   11.23 
             Ba(138)  137.905236   71.70                                                             

Beryllium    Be(9)      9.012183  100.00                                                             
Bismuth      Bi(209)  208.980388  100.00                                                             
Boron        B(10)     10.012938   19.80    B(11)     11.009305   80.20                               
Bromine      Br(79)    78.918336   50.69    Br(81)    80.916290   49.31                               
Cadmium      Cd(106)  105.906461  1.25  Cd(108)  107.904186  0.89   Cd(110)  109.903007   12.49    Cd(111)  110.904182   12.80 
             Cd(112)  111.902761   24.13    Cd(113)  112.904401   12.22    Cd(114)  113.903361   28.73 
             Cd(116)  115.904758    7.49 

Calcium      Ca(40)    39.962591   96.95    Ca(42)    41.958622    0.65    Ca(43)    42.958770    0.14 
             Ca(44)    43.955485   2.086    Ca(46)    45.953689   0.004    Ca(48)    47.952532    0.19 
Carbon       C(12)     12.000000   98.90    C(13)     13.003355    1.10                               
Cerium       Ce(136)  135.907140    0.19    Ce(138)  137.905996    0.25    Ce(140)  139.905442   88.48 
             Ce(142)  141.909249   11.08                                                             
Cesium       Cs(133)  132.905433  100.00                                                             
Chlorine     Cl(35)    34.968853   75.77    Cl(37)    36.965903   24.23                               

Chromium     Cr(50)    49.946046    4.35    Cr(52)    51.940510   83.79    Cr(53)    52.940651    9.50 
             Cr(54)    53.938882    2.36                                                             
Cobalt       Co(59)    58.933198  100.00                                                             
Copper       Cu(63)    62.929599   69.17    Cu(65)    64.927792   30.83                               
Dysprosium   Dy(156)  155.924287   0.060    Dy(158)  157.924412    0.10    Dy(160)  159.925203    2.34 
             Dy(161)  160.926939   18.90    Dy(162)  161.926805   25.50    Dy(163)  162.928737   24.90 
             Dy(164)  163.929183   28.20                                                             
Erbium       Er(162)  161.928787    0.14    Er(164)  163.929211    1.61    Er(166)  165.930305   33.60 
             Er(167)  166.932061   22.95    Er(168)  167.932383   26.80    Er(170)  169.935476   14.90 


Europium     Eu(151)  150.919860   47.80    Eu(153)  152.921243   52.20                               
Fluorine     F(19)     18.998403  100.00                                                             
Gallium      Ga(69)    68.925581   60.10    Ga(71)    70.924701   39.90                               
Gadolinium   Gd(152)  151.919803   0.200    Gd(154)  153.920876    2.18    Gd(155)  154.822629   14.80 
             Gd(156)  155.922130   20.47    Gd(157)  156.923967   15.65    Gd(158)  157.924111   24.84 
             Gd(160)  159.927061   21.86                                                             
Germanium    Ge(70)    69.924250   20.50    Ge(72)    71.922080   27.40    Ge(73)    72.923464    7.80 
             Ge(74)    73.921179   36.50    Ge(76)    75.921403    7.80                               

Gold         Au(197)  196.966560  100.00                                                             
Hafnium      Hf(174)  173.940065    0.16    Hf(176)  175.941420    5.20    Hf(177)  176.943233   18.60 
             Hf(178)  177.943710   27.10    Hf(179)  178.945827   13.74    Hf(180)  179.946561   35.20 
Helium       He(3)      3.016029   .0001    He(4)      4.002603  100.00                               
Holmium      Ho(165)  164.930332  100.00                                                             
Hydrogen     H(1)       1.007825   99.99    H(2)       2.014102   0.015   

Indium       In(113)  112.904056    4.30    In(115)  114.903875   95.70                               
Iodine       I(127)   126.904477  100.00                                                             
Iridium      Ir(191)  190.960603   37.30    Ir(193)  192.962942   62.70                               
Iron         Fe(54)    53.939612    5.80    Fe(56)    55.934939   91.72    Fe(57)    56.935396    2.20 
             Fe(58)    57.933278    0.28                                                             
Krypton      Kr(78)    77.920397    0.35    Kr(80)    79.916375    2.25    Kr(82)    81.913483   11.60 
             Kr(83)    82.914134   11.50    Kr(84)    83.911506   57.00    Kr(86)    85.910614   17.30 

Lanthanum    La(138)  137.907114    0.09    La(139)  138.906355   99.91                               
Lead         Pb(204)  203.973037    1.40    Pb(206)  205.974455   24.10    Pb(207)  206.975885   22.10 
             Pb(208)  207.976641   52.40                                                             
Lithium      Li(6)      6.015123    7.42    Li(7)      7.016005   92.58                               
Lutetium     Lu(175)  174.940785   97.40    Lu(176)  175.942694    2.60                               
Magnesium    Mg(24)    23.985045   78.90    Mg(25)    24.985839   10.00    Mg(26)    25.982595   11.10 

Manganese    Mn(55)    54.938046  100.00                                                             
Mercury      Hg(196)  195.965812    0.15    Hg(198)  197.966760   10.10    Hg(199)  198.968269   17.00 
             Hg(200)  199.968316   23.10    Hg(201)  200.970293   13.20    Hg(202)  201.970632   29.65 
             Hg(204)  203.973481    6.80                                                             
Molybdenum   Mo(92)    91.906809   14.84    Mo(94)    93.905086    9.25    Mo(95)    94.905838   15.92 
             Mo(96)    95.904676   16.68    Mo(97)    96.906018    9.55    Mo(98)    97.905405   24.13 
             Mo(100)   99.907473    9.63                                                             
Neodymium    Nd(142)  141.907731   27.13    Nd(143)  142.909823   12.18    Nd(144)  143.910096   23.80 
             Nd(145)  144.912582    8.30    Nd(146)  145.913126   17.19    Nd(148)  147.916901    5.76 
             Nd(150)  149.920900    5.64                                                             
Neon         Ne(20)    19.992439   90.60    Ne(21)    20.993845    0.26    Ne(22)    21.991384    9.20 

Nickel       Ni(58)    57.935347   68.27    Ni(60)    59.930789   26.10    Ni(61)    60.931059    1.13 
             Ni(62)    61.928346    3.59    Ni(64)    63.927968    0.91                               
Niobium      Nb(93)    92.906378  100.00                                                             
Nitrogen     N(14)     14.003074   99.63    N(15)     15.000109    0.37                               
Osmium       Os(184)  183.952514    0.02    Os(186)  185.953852    1.58    Os(187)  186.955762    1.60 
             Os(188)  187.955850   13.30    Os(189)  188.958156   16.10    Os(190)  189.958455   26.40 
             Os(192)  191.961487   41.00                                                             
Oxygen       O(16)     15.994915   99.76    O(17)     16.999131   0.038    O(18)     17.999159    0.20 

Palladium    Pd(102)  101.905609    1.02    Pd(104)  103.904026   11.14    Pd(105)  104.905075   22.33 
             Pd(106)  105.903475    27.33   Pd(108)  107.903894   26.46    Pd(110)  109.905169   11.72 
Phosphorus   P(31)     30.973763  100.00                                                             
Platinum     Pt(190)  189.959937   0.010    Pt(192)  191.961049    0.79    Pt(194)  193.962679   32.90 
             Pt(195)  194.964785   33.80    Pt(196)  195.964947   25.30    Pt(198)  197.967879    7.20 
Potassium    K(39)     38.963708   93.20    K(40)     39.963999   0.012    K(41)     40.961825    6.73 
Praseodymium Pr(141)  140.907657  100.00                                                             

Rhenium      Re(185)  184.952977   37.40    Re(187)  186.955765   62.60                               
Rhodium      Rh(103)  102.905503  100.00                                                             
Rubidium     Rb(85)    84.911800   72.17    Rb(87)    86.909184   27.84                               
Ruthenium    Ru(96)    95.907596    5.52    Ru(98)    97.905287    1.88    Ru(99)    98.905937   12.70 
             Ru(100)   99.904218   12.60    Ru(101)  100.905581   17.00    Ru(102)  101.904348   31.60 
             Ru(104)  103.905422   18.70                                                             
Samarium     Sm(144)  143.912009    3.10    Sm(147)  146.914907   15.00    Sm(148)  147.914832   11.30 
             Sm(149)  148.917193   13.80    Sm(150)  149.917285    7.40    Sm(152)  151.919741   26.70 
             Sm(154)  153.922218   22.70                                                             

Scandium     Sc(45)    44.955914  100.00                                                             
Selenium     Se(74)    73.922477    0.90    Se(76)    75.919207    9.00    Se(77)    76.919908    7.60 
             Se(78)    77.917304   23.50    Se(80)    79.916521   49.60    Se(82)    81.916709    9.40 
Silicon      Si(28)    27.976928   92.23    Si(29)    28.976496    4.67    Si(30)    29.973772    3.10 
Silver       Ag(107)  106.905095   51.84    Ag(109)  108.904754   48.16                               
Sodium       Na(23)    22.989770  100.00                                                             

Strontium    Sr(84)    83.913428    0.56    Sr(86)    85.909273    9.86    Sr(87)    86.908902    7.00 
             Sr(88)    87.905625   82.58                                                             
Sulfur       S(32)     31.972072   95.02    S(33)     32.971459    0.75    S(34)     33.967868    4.21 
             S(36)     35.967079   0.020                                                             
Tantalum     Ta(180)  179.947489   0.012    Ta(181)  180.948014   99.99                               
Tellurium    Te(120)  119.904021 0.096  Te(122)  121.903055    2.60    Te(123)  122.904278    0.91
             Te(124)  123.902825    4.82 Te(125)  124.904435    7.14    Te(126)  125.903310 18.95
             Te(128)  127.904464   31.69 Te(130)  129.906229   33.80                                                             
Terbium      Tb(159)  158.925350  100.00                                                             

Thallium     Tl(203)  202.972336   29.52    Tl(205)  204.974410   70.48                               
Thorium      Th(232)  232.038054  100.00                                                             
Thulium      Tm(169)  168.934225  100.00                                                             
Tin          Sn(112)  111.904826  0.97      Sn(114)  113.902784  0.65  Sn(115)  114.903348 0.36
             Sn(116)  115.901744   14.70    Sn(117)  116.902954    7.70    Sn(118)  117.901607   24.30 
             Sn(119)  118.903310    8.60    Sn(120)  119.902199   32.40    Sn(122)  121.903440    4.60 
             Sn(124)  123.905271    5.60                                                             
Titanium     Ti(46)    45.952633    8.00    Ti(47)    46.951765    7.30    Ti(48)    47.947947   73.80 
             Ti(49)    48.947871    5.50    Ti(50)    49.944786    5.40                               

Tungsten     W(180)   179.946727    0.13    W(182)   181.948225   26.30    W(183)   182.950245   14.30 
             W(184)   183.950953   30.67    W(186)   185.954377   28.60                               
Uranium      U(234)   234.040947   0.006    U(235)   235.043925    0.72    U(238)   238.050786   99.27 
Vanadium     V(50)     49.947161    0.25    V(51)     50.943963   99.75                               
Xenon        Xe(124)  123.905894    0.10    X(126)   125.904281   0.09
             Xe(128)  127.903531    1.91    Xe(129)  128.904780   26.40    Xe(130)  129.903510    4.10 
             Xe(131)  130.905076   21.20    Xe(132)  131.904148   26.90    Xe(134)  133.905395   10.40 
             Xe(136)  135.907219    8.90                                                             
Ytterbium    Yb(168)  167.933908    0.13    Yb(170)  169.934774    3.05    Yb(171)  170.936338   14.30 
             Yb(172)  171.936393   21.90    Yb(173)  172.938222   16.12    Yb(174)  173.938873   31.80 
             Yb(176)  175.942576   12.70                                                             

Yttrium      Y(89)     88.905856  100.00                                                             
Zinc         Zn(64)    63.929145   48.60    Zn(66)    65.926035   27.90    Zn(67)    66.927129    4.10 
             Zn(68)    67.924846   18.80    Zn(70)    69.925325    0.60                               
Zirconium    Zr(90)    89.904708   51.45    Zr(91)    90.905644   11.27    Zr(92)    91.905039   17.17 
             Zr(94)    93.906319   17.33    Zr(96)    95.908272    2.78                               

Authors not responsible for errors, omissions or inaccuracy of the above data. Please notify SIS of any errors or corrections in the above data.

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