Atomic Number = 1 Atomic Symbol = H Mass Number = 1 Relative Atomic Mass = 1.00782503223(9) Isotopic Composition = 0.999885(70) Standard Atomic Weight = [1.00784,1.00811] Notes = m Atomic Number = 1 Atomic Symbol = D Mass Number = 2 Relative Atomic Mass = 2.01410177812(12) Isotopic Composition = 0.000115(70) Standard Atomic Weight = [1.00784,1.00811] Notes = m Atomic Number = 1 Atomic Symbol = T Mass Number = 3 Relative Atomic Mass = 3.0160492779(24) Isotopic Composition = Standard Atomic Weight = [1.00784,1.00811] Notes = m Atomic Number = 2 Atomic Symbol = He Mass Number = 3 Relative Atomic Mass = 3.0160293201(25) Isotopic Composition = 0.00000134(3) Standard Atomic Weight = 4.002602(2) Notes = g,r Atomic Number = 2 Atomic Symbol = He Mass Number = 4 Relative Atomic Mass = 4.00260325413(6) Isotopic Composition = 0.99999866(3) Standard Atomic Weight = 4.002602(2) Notes = g,r Atomic Number = 3 Atomic Symbol = Li Mass Number = 6 Relative Atomic Mass = 6.0151228874(16) Isotopic Composition = 0.0759(4) Standard Atomic Weight = [6.938,6.997] Notes = m Atomic Number = 3 Atomic Symbol = Li Mass Number = 7 Relative Atomic Mass = 7.0160034366(45) Isotopic Composition = 0.9241(4) Standard Atomic Weight = [6.938,6.997] Notes = m Atomic Number = 4 Atomic Symbol = Be Mass Number = 9 Relative Atomic Mass = 9.012183065(82) Isotopic Composition = 1 Standard Atomic Weight = 9.0121831(5) Notes =   Atomic Number = 5 Atomic Symbol = B Mass Number = 10 Relative Atomic Mass = 10.01293695(41) Isotopic Composition = 0.199(7) Standard Atomic Weight = [10.806,10.821] Notes = m Atomic Number = 5 Atomic Symbol = B Mass Number = 11 Relative Atomic Mass = 11.00930536(45) Isotopic Composition = 0.801(7) Standard Atomic Weight = [10.806,10.821] Notes = m Atomic Number = 6 Atomic Symbol = C Mass Number = 12 Relative Atomic Mass = 12.0000000(00) Isotopic Composition = 0.9893(8) Standard Atomic Weight = [12.0096,12.0116] Notes =   Atomic Number = 6 Atomic Symbol = C Mass Number = 13 Relative Atomic Mass = 13.00335483507(23) Isotopic Composition = 0.0107(8) Standard Atomic Weight = [12.0096,12.0116] Notes =   Atomic Number = 6 Atomic Symbol = C Mass Number = 14 Relative Atomic Mass = 14.0032419884(40) Isotopic Composition = Standard Atomic Weight = [12.0096,12.0116] Notes =   Atomic Number = 7 Atomic Symbol = N Mass Number = 14 Relative Atomic Mass = 14.00307400443(20) Isotopic Composition = 0.99636(20) Standard Atomic Weight = [14.00643,14.00728] Notes =   Atomic Number = 7 Atomic Symbol = N Mass Number = 15 Relative Atomic Mass = 15.00010889888(64) Isotopic Composition = 0.00364(20) Standard Atomic Weight = [14.00643,14.00728] Notes =   Atomic Number = 8 Atomic Symbol = O Mass Number = 16 Relative Atomic Mass = 15.99491461957(17) Isotopic Composition = 0.99757(16) Standard Atomic Weight = [15.99903,15.99977] Notes =   Atomic Number = 8 Atomic Symbol = O Mass Number = 17 Relative Atomic Mass = 16.99913175650(69) Isotopic Composition = 0.00038(1) Standard Atomic Weight = [15.99903,15.99977] Notes =   Atomic Number = 8 Atomic Symbol = O Mass Number = 18 Relative Atomic Mass = 17.99915961286(76) Isotopic Composition = 0.00205(14) Standard Atomic Weight = [15.99903,15.99977] Notes =   Atomic Number = 9 Atomic Symbol = F Mass Number = 19 Relative Atomic Mass = 18.99840316273(92) Isotopic Composition = 1 Standard Atomic Weight = 18.998403163(6) Notes =   Atomic Number = 10 Atomic Symbol = Ne Mass Number = 20 Relative Atomic Mass = 19.9924401762(17) Isotopic Composition = 0.9048(3) Standard Atomic Weight = 20.1797(6) Notes = g,m Atomic Number = 10 Atomic Symbol = Ne Mass Number = 21 Relative Atomic Mass = 20.993846685(41) Isotopic Composition = 0.0027(1) Standard Atomic Weight = 20.1797(6) Notes = g,m Atomic Number = 10 Atomic Symbol = Ne Mass Number = 22 Relative Atomic Mass = 21.991385114(18) Isotopic Composition = 0.0925(3) Standard Atomic Weight = 20.1797(6) Notes = g,m Atomic Number = 11 Atomic Symbol = Na Mass Number = 23 Relative Atomic Mass = 22.9897692820(19) Isotopic Composition = 1 Standard Atomic Weight = 22.98976928(2) Notes =   Atomic Number = 12 Atomic Symbol = Mg Mass Number = 24 Relative Atomic Mass = 23.985041697(14) Isotopic Composition = 0.7899(4) Standard Atomic Weight = [24.304,24.307] Notes =   Atomic Number = 12 Atomic Symbol = Mg Mass Number = 25 Relative Atomic Mass = 24.985836976(50) Isotopic Composition = 0.1000(1) Standard Atomic Weight = [24.304,24.307] Notes =   Atomic Number = 12 Atomic Symbol = Mg Mass Number = 26 Relative Atomic Mass = 25.982592968(31) Isotopic Composition = 0.1101(3) Standard Atomic Weight = [24.304,24.307] Notes =   Atomic Number = 13 Atomic Symbol = Al Mass Number = 27 Relative Atomic Mass = 26.98153853(11) Isotopic Composition = 1 Standard Atomic Weight = 26.9815385(7) Notes =   Atomic Number = 14 Atomic Symbol = Si Mass Number = 28 Relative Atomic Mass = 27.97692653465(44) Isotopic Composition = 0.92223(19) Standard Atomic Weight = [28.084,28.086] Notes =   Atomic Number = 14 Atomic Symbol = Si Mass Number = 29 Relative Atomic Mass = 28.97649466490(52) Isotopic Composition = 0.04685(8) Standard Atomic Weight = [28.084,28.086] Notes =   Atomic Number = 14 Atomic Symbol = Si Mass Number = 30 Relative Atomic Mass = 29.973770136(23) Isotopic Composition = 0.03092(11) Standard Atomic Weight = [28.084,28.086] Notes =   Atomic Number = 15 Atomic Symbol = P Mass Number = 31 Relative Atomic Mass = 30.97376199842(70) Isotopic Composition = 1 Standard Atomic Weight = 30.973761998(5) Notes =   Atomic Number = 16 Atomic Symbol = S Mass Number = 32 Relative Atomic Mass = 31.9720711744(14) Isotopic Composition = 0.9499(26) Standard Atomic Weight = [32.059,32.076] Notes =   Atomic Number = 16 Atomic Symbol = S Mass Number = 33 Relative Atomic Mass = 32.9714589098(15) Isotopic Composition = 0.0075(2) Standard Atomic Weight = [32.059,32.076] Notes =   Atomic Number = 16 Atomic Symbol = S Mass Number = 34 Relative Atomic Mass = 33.967867004(47) Isotopic Composition = 0.0425(24) Standard Atomic Weight = [32.059,32.076] Notes =   Atomic Number = 16 Atomic Symbol = S Mass Number = 36 Relative Atomic Mass = 35.96708071(20) Isotopic Composition = 0.0001(1) Standard Atomic Weight = [32.059,32.076] Notes =   Atomic Number = 17 Atomic Symbol = Cl Mass Number = 35 Relative Atomic Mass = 34.968852682(37) Isotopic Composition = 0.7576(10) Standard Atomic Weight = [35.446,35.457] Notes = m Atomic Number = 17 Atomic Symbol = Cl Mass Number = 37 Relative Atomic Mass = 36.965902602(55) Isotopic Composition = 0.2424(10) Standard Atomic Weight = [35.446,35.457] Notes = m Atomic Number = 18 Atomic Symbol = Ar Mass Number = 36 Relative Atomic Mass = 35.967545105(28) Isotopic Composition = 0.003336(21) Standard Atomic Weight = 39.948(1) Notes = g,r Atomic Number = 18 Atomic Symbol = Ar Mass Number = 38 Relative Atomic Mass = 37.96273211(21) Isotopic Composition = 0.000629(7) Standard Atomic Weight = 39.948(1) Notes = g,r Atomic Number = 18 Atomic Symbol = Ar Mass Number = 40 Relative Atomic Mass = 39.9623831237(24) Isotopic Composition = 0.996035(25) Standard Atomic Weight = 39.948(1) Notes = g,r Atomic Number = 19 Atomic Symbol = K Mass Number = 39 Relative Atomic Mass = 38.9637064864(49) Isotopic Composition = 0.932581(44) Standard Atomic Weight = 39.0983(1) Notes =   Atomic Number = 19 Atomic Symbol = K Mass Number = 40 Relative Atomic Mass = 39.963998166(60) Isotopic Composition = 0.000117(1) Standard Atomic Weight = 39.0983(1) Notes =   Atomic Number = 19 Atomic Symbol = K Mass Number = 41 Relative Atomic Mass = 40.9618252579(41) Isotopic Composition = 0.067302(44) Standard Atomic Weight = 39.0983(1) Notes =   Atomic Number = 20 Atomic Symbol = Ca Mass Number = 40 Relative Atomic Mass = 39.962590863(22) Isotopic Composition = 0.96941(156) Standard Atomic Weight = 40.078(4) Notes = g Atomic Number = 20 Atomic Symbol = Ca Mass Number = 42 Relative Atomic Mass = 41.95861783(16) Isotopic Composition = 0.00647(23) Standard Atomic Weight = 40.078(4) Notes = g Atomic Number = 20 Atomic Symbol = Ca Mass Number = 43 Relative Atomic Mass = 42.95876644(24) Isotopic Composition = 0.00135(10) Standard Atomic Weight = 40.078(4) Notes = g Atomic Number = 20 Atomic Symbol = Ca Mass Number = 44 Relative Atomic Mass = 43.95548156(35) Isotopic Composition = 0.02086(110) Standard Atomic Weight = 40.078(4) Notes = g Atomic Number = 20 Atomic Symbol = Ca Mass Number = 46 Relative Atomic Mass = 45.9536890(24) Isotopic Composition = 0.00004(3) Standard Atomic Weight = 40.078(4) Notes = g Atomic Number = 20 Atomic Symbol = Ca Mass Number = 48 Relative Atomic Mass = 47.95252276(13) Isotopic Composition = 0.00187(21) Standard Atomic Weight = 40.078(4) Notes = g Atomic Number = 21 Atomic Symbol = Sc Mass Number = 45 Relative Atomic Mass = 44.95590828(77) Isotopic Composition = 1 Standard Atomic Weight = 44.955908(5) Notes =   Atomic Number = 22 Atomic Symbol = Ti Mass Number = 46 Relative Atomic Mass = 45.95262772(35) Isotopic Composition = 0.0825(3) Standard Atomic Weight = 47.867(1) Notes =   Atomic Number = 22 Atomic Symbol = Ti Mass Number = 47 Relative Atomic Mass = 46.95175879(38) Isotopic Composition = 0.0744(2) Standard Atomic Weight = 47.867(1) Notes =   Atomic Number = 22 Atomic Symbol = Ti Mass Number = 48 Relative Atomic Mass = 47.94794198(38) Isotopic Composition = 0.7372(3) Standard Atomic Weight = 47.867(1) Notes =   Atomic Number = 22 Atomic Symbol = Ti Mass Number = 49 Relative Atomic Mass = 48.94786568(39) Isotopic Composition = 0.0541(2) Standard Atomic Weight = 47.867(1) Notes =   Atomic Number = 22 Atomic Symbol = Ti Mass Number = 50 Relative Atomic Mass = 49.94478689(39) Isotopic Composition = 0.0518(2) Standard Atomic Weight = 47.867(1) Notes =   Atomic Number = 23 Atomic Symbol = V Mass Number = 50 Relative Atomic Mass = 49.94715601(95) Isotopic Composition = 0.00250(4) Standard Atomic Weight = 50.9415(1) Notes =   Atomic Number = 23 Atomic Symbol = V Mass Number = 51 Relative Atomic Mass = 50.94395704(94) Isotopic Composition = 0.99750(4) Standard Atomic Weight = 50.9415(1) Notes =   Atomic Number = 24 Atomic Symbol = Cr Mass Number = 50 Relative Atomic Mass = 49.94604183(94) Isotopic Composition = 0.04345(13) Standard Atomic Weight = 51.9961(6) Notes =   Atomic Number = 24 Atomic Symbol = Cr Mass Number = 52 Relative Atomic Mass = 51.94050623(63) Isotopic Composition = 0.83789(18) Standard Atomic Weight = 51.9961(6) Notes =   Atomic Number = 24 Atomic Symbol = Cr Mass Number = 53 Relative Atomic Mass = 52.94064815(62) Isotopic Composition = 0.09501(17) Standard Atomic Weight = 51.9961(6) Notes =   Atomic Number = 24 Atomic Symbol = Cr Mass Number = 54 Relative Atomic Mass = 53.93887916(61) Isotopic Composition = 0.02365(7) Standard Atomic Weight = 51.9961(6) Notes =   Atomic Number = 25 Atomic Symbol = Mn Mass Number = 55 Relative Atomic Mass = 54.93804391(48) Isotopic Composition = 1 Standard Atomic Weight = 54.938044(3) Notes =   Atomic Number = 26 Atomic Symbol = Fe Mass Number = 54 Relative Atomic Mass = 53.93960899(53) Isotopic Composition = 0.05845(35) Standard Atomic Weight = 55.845(2) Notes =   Atomic Number = 26 Atomic Symbol = Fe Mass Number = 56 Relative Atomic Mass = 55.93493633(49) Isotopic Composition = 0.91754(36) Standard Atomic Weight = 55.845(2) Notes =   Atomic Number = 26 Atomic Symbol = Fe Mass Number = 57 Relative Atomic Mass = 56.93539284(49) Isotopic Composition = 0.02119(10) Standard Atomic Weight = 55.845(2) Notes =   Atomic Number = 26 Atomic Symbol = Fe Mass Number = 58 Relative Atomic Mass = 57.93327443(53) Isotopic Composition = 0.00282(4) Standard Atomic Weight = 55.845(2) Notes =   Atomic Number = 27 Atomic Symbol = Co Mass Number = 59 Relative Atomic Mass = 58.93319429(56) Isotopic Composition = 1 Standard Atomic Weight = 58.933194(4) Notes =   Atomic Number = 28 Atomic Symbol = Ni Mass Number = 58 Relative Atomic Mass = 57.93534241(52) Isotopic Composition = 0.68077(19) Standard Atomic Weight = 58.6934(4) Notes = r Atomic Number = 28 Atomic Symbol = Ni Mass Number = 60 Relative Atomic Mass = 59.93078588(52) Isotopic Composition = 0.26223(15) Standard Atomic Weight = 58.6934(4) Notes = r Atomic Number = 28 Atomic Symbol = Ni Mass Number = 61 Relative Atomic Mass = 60.93105557(52) Isotopic Composition = 0.011399(13) Standard Atomic Weight = 58.6934(4) Notes = r Atomic Number = 28 Atomic Symbol = Ni Mass Number = 62 Relative Atomic Mass = 61.92834537(55) Isotopic Composition = 0.036346(40) Standard Atomic Weight = 58.6934(4) Notes = r Atomic Number = 28 Atomic Symbol = Ni Mass Number = 64 Relative Atomic Mass = 63.92796682(58) Isotopic Composition = 0.009255(19) Standard Atomic Weight = 58.6934(4) Notes = r Atomic Number = 29 Atomic Symbol = Cu Mass Number = 63 Relative Atomic Mass = 62.92959772(56) Isotopic Composition = 0.6915(15) Standard Atomic Weight = 63.546(3) Notes = r Atomic Number = 29 Atomic Symbol = Cu Mass Number = 65 Relative Atomic Mass = 64.92778970(71) Isotopic Composition = 0.3085(15) Standard Atomic Weight = 63.546(3) Notes = r Atomic Number = 30 Atomic Symbol = Zn Mass Number = 64 Relative Atomic Mass = 63.92914201(71) Isotopic Composition = 0.4917(75) Standard Atomic Weight = 65.38(2) Notes = r Atomic Number = 30 Atomic Symbol = Zn Mass Number = 66 Relative Atomic Mass = 65.92603381(94) Isotopic Composition = 0.2773(98) Standard Atomic Weight = 65.38(2) Notes = r Atomic Number = 30 Atomic Symbol = Zn Mass Number = 67 Relative Atomic Mass = 66.92712775(96) Isotopic Composition = 0.0404(16) Standard Atomic Weight = 65.38(2) Notes = r Atomic Number = 30 Atomic Symbol = Zn Mass Number = 68 Relative Atomic Mass = 67.92484455(98) Isotopic Composition = 0.1845(63) Standard Atomic Weight = 65.38(2) Notes = r Atomic Number = 30 Atomic Symbol = Zn Mass Number = 70 Relative Atomic Mass = 69.9253192(21) Isotopic Composition = 0.0061(10) Standard Atomic Weight = 65.38(2) Notes = r Atomic Number = 31 Atomic Symbol = Ga Mass Number = 69 Relative Atomic Mass = 68.9255735(13) Isotopic Composition = 0.60108(9) Standard Atomic Weight = 69.723(1) Notes =   Atomic Number = 31 Atomic Symbol = Ga Mass Number = 71 Relative Atomic Mass = 70.92470258(87) Isotopic Composition = 0.39892(9) Standard Atomic Weight = 69.723(1) Notes =   Atomic Number = 32 Atomic Symbol = Ge Mass Number = 70 Relative Atomic Mass = 69.92424875(90) Isotopic Composition = 0.2057(27) Standard Atomic Weight = 72.630(8) Notes =   Atomic Number = 32 Atomic Symbol = Ge Mass Number = 72 Relative Atomic Mass = 71.922075826(81) Isotopic Composition = 0.2745(32) Standard Atomic Weight = 72.630(8) Notes =   Atomic Number = 32 Atomic Symbol = Ge Mass Number = 73 Relative Atomic Mass = 72.923458956(61) Isotopic Composition = 0.0775(12) Standard Atomic Weight = 72.630(8) Notes =   Atomic Number = 32 Atomic Symbol = Ge Mass Number = 74 Relative Atomic Mass = 73.921177761(13) Isotopic Composition = 0.3650(20) Standard Atomic Weight = 72.630(8) Notes =   Atomic Number = 32 Atomic Symbol = Ge Mass Number = 76 Relative Atomic Mass = 75.921402726(19) Isotopic Composition = 0.0773(12) Standard Atomic Weight = 72.630(8) Notes =   Atomic Number = 33 Atomic Symbol = As Mass Number = 75 Relative Atomic Mass = 74.92159457(95) Isotopic Composition = 1 Standard Atomic Weight = 74.921595(6) Notes =   Atomic Number = 34 Atomic Symbol = Se Mass Number = 74 Relative Atomic Mass = 73.922475934(15) Isotopic Composition = 0.0089(4) Standard Atomic Weight = 78.971(8) Notes = r Atomic Number = 34 Atomic Symbol = Se Mass Number = 76 Relative Atomic Mass = 75.919213704(17) Isotopic Composition = 0.0937(29) Standard Atomic Weight = 78.971(8) Notes = r Atomic Number = 34 Atomic Symbol = Se Mass Number = 77 Relative Atomic Mass = 76.919914154(67) Isotopic Composition = 0.0763(16) Standard Atomic Weight = 78.971(8) Notes = r Atomic Number = 34 Atomic Symbol = Se Mass Number = 78 Relative Atomic Mass = 77.91730928(20) Isotopic Composition = 0.2377(28) Standard Atomic Weight = 78.971(8) Notes = r Atomic Number = 34 Atomic Symbol = Se Mass Number = 80 Relative Atomic Mass = 79.9165218(13) Isotopic Composition = 0.4961(41) Standard Atomic Weight = 78.971(8) Notes = r Atomic Number = 34 Atomic Symbol = Se Mass Number = 82 Relative Atomic Mass = 81.9166995(15) Isotopic Composition = 0.0873(22) Standard Atomic Weight = 78.971(8) Notes = r Atomic Number = 35 Atomic Symbol = Br Mass Number = 79 Relative Atomic Mass = 78.9183376(14) Isotopic Composition = 0.5069(7) Standard Atomic Weight = [79.901,79.907] Notes =   Atomic Number = 35 Atomic Symbol = Br Mass Number = 81 Relative Atomic Mass = 80.9162897(14) Isotopic Composition = 0.4931(7) Standard Atomic Weight = [79.901,79.907] Notes =   Atomic Number = 36 Atomic Symbol = Kr Mass Number = 78 Relative Atomic Mass = 77.92036494(76) Isotopic Composition = 0.00355(3) Standard Atomic Weight = 83.798(2) Notes = g,m Atomic Number = 36 Atomic Symbol = Kr Mass Number = 80 Relative Atomic Mass = 79.91637808(75) Isotopic Composition = 0.02286(10) Standard Atomic Weight = 83.798(2) Notes = g,m Atomic Number = 36 Atomic Symbol = Kr Mass Number = 82 Relative Atomic Mass = 81.91348273(94) Isotopic Composition = 0.11593(31) Standard Atomic Weight = 83.798(2) Notes = g,m Atomic Number = 36 Atomic Symbol = Kr Mass Number = 83 Relative Atomic Mass = 82.91412716(32) Isotopic Composition = 0.11500(19) Standard Atomic Weight = 83.798(2) Notes = g,m Atomic Number = 36 Atomic Symbol = Kr Mass Number = 84 Relative Atomic Mass = 83.9114977282(44) Isotopic Composition = 0.56987(15) Standard Atomic Weight = 83.798(2) Notes = g,m Atomic Number = 36 Atomic Symbol = Kr Mass Number = 86 Relative Atomic Mass = 85.9106106269(41) Isotopic Composition = 0.17279(41) Standard Atomic Weight = 83.798(2) Notes = g,m Atomic Number = 37 Atomic Symbol = Rb Mass Number = 85 Relative Atomic Mass = 84.9117897379(54) Isotopic Composition = 0.7217(2) Standard Atomic Weight = 85.4678(3) Notes = g Atomic Number = 37 Atomic Symbol = Rb Mass Number = 87 Relative Atomic Mass = 86.9091805310(60) Isotopic Composition = 0.2783(2) Standard Atomic Weight = 85.4678(3) Notes = g Atomic Number = 38 Atomic Symbol = Sr Mass Number = 84 Relative Atomic Mass = 83.9134191(13) Isotopic Composition = 0.0056(1) Standard Atomic Weight = 87.62(1) Notes = g,r Atomic Number = 38 Atomic Symbol = Sr Mass Number = 86 Relative Atomic Mass = 85.9092606(12) Isotopic Composition = 0.0986(1) Standard Atomic Weight = 87.62(1) Notes = g,r Atomic Number = 38 Atomic Symbol = Sr Mass Number = 87 Relative Atomic Mass = 86.9088775(12) Isotopic Composition = 0.0700(1) Standard Atomic Weight = 87.62(1) Notes = g,r Atomic Number = 38 Atomic Symbol = Sr Mass Number = 88 Relative Atomic Mass = 87.9056125(12) Isotopic Composition = 0.8258(1) Standard Atomic Weight = 87.62(1) Notes = g,r Atomic Number = 39 Atomic Symbol = Y Mass Number = 89 Relative Atomic Mass = 88.9058403(24) Isotopic Composition = 1 Standard Atomic Weight = 88.90584(2) Notes =   Atomic Number = 40 Atomic Symbol = Zr Mass Number = 90 Relative Atomic Mass = 89.9046977(20) Isotopic Composition = 0.5145(40) Standard Atomic Weight = 91.224(2) Notes = g Atomic Number = 40 Atomic Symbol = Zr Mass Number = 91 Relative Atomic Mass = 90.9056396(20) Isotopic Composition = 0.1122(5) Standard Atomic Weight = 91.224(2) Notes = g Atomic Number = 40 Atomic Symbol = Zr Mass Number = 92 Relative Atomic Mass = 91.9050347(20) Isotopic Composition = 0.1715(8) Standard Atomic Weight = 91.224(2) Notes = g Atomic Number = 40 Atomic Symbol = Zr Mass Number = 94 Relative Atomic Mass = 93.9063108(20) Isotopic Composition = 0.1738(28) Standard Atomic Weight = 91.224(2) Notes = g Atomic Number = 40 Atomic Symbol = Zr Mass Number = 96 Relative Atomic Mass = 95.9082714(21) Isotopic Composition = 0.0280(9) Standard Atomic Weight = 91.224(2) Notes = g Atomic Number = 41 Atomic Symbol = Nb Mass Number = 93 Relative Atomic Mass = 92.9063730(20) Isotopic Composition = 1 Standard Atomic Weight = 92.90637(2) Notes =   Atomic Number = 42 Atomic Symbol = Mo Mass Number = 92 Relative Atomic Mass = 91.90680796(84) Isotopic Composition = 0.1453(30) Standard Atomic Weight = 95.95(1) Notes = g Atomic Number = 42 Atomic Symbol = Mo Mass Number = 94 Relative Atomic Mass = 93.90508490(48) Isotopic Composition = 0.0915(9) Standard Atomic Weight = 95.95(1) Notes = g Atomic Number = 42 Atomic Symbol = Mo Mass Number = 95 Relative Atomic Mass = 94.90583877(47) Isotopic Composition = 0.1584(11) Standard Atomic Weight = 95.95(1) Notes = g Atomic Number = 42 Atomic Symbol = Mo Mass Number = 96 Relative Atomic Mass = 95.90467612(47) Isotopic Composition = 0.1667(15) Standard Atomic Weight = 95.95(1) Notes = g Atomic Number = 42 Atomic Symbol = Mo Mass Number = 97 Relative Atomic Mass = 96.90601812(49) Isotopic Composition = 0.0960(14) Standard Atomic Weight = 95.95(1) Notes = g Atomic Number = 42 Atomic Symbol = Mo Mass Number = 98 Relative Atomic Mass = 97.90540482(49) Isotopic Composition = 0.2439(37) Standard Atomic Weight = 95.95(1) Notes = g Atomic Number = 42 Atomic Symbol = Mo Mass Number = 100 Relative Atomic Mass = 99.9074718(11) Isotopic Composition = 0.0982(31) Standard Atomic Weight = 95.95(1) Notes = g Atomic Number = 43 Atomic Symbol = Tc Mass Number = 97 Relative Atomic Mass = 96.9063667(40) Isotopic Composition = Standard Atomic Weight = [98] Notes =   Atomic Number = 43 Atomic Symbol = Tc Mass Number = 98 Relative Atomic Mass = 97.9072124(36) Isotopic Composition = Standard Atomic Weight = [98] Notes =   Atomic Number = 43 Atomic Symbol = Tc Mass Number = 99 Relative Atomic Mass = 98.9062508(10) Isotopic Composition = Standard Atomic Weight = [98] Notes =   Atomic Number = 44 Atomic Symbol = Ru Mass Number = 96 Relative Atomic Mass = 95.90759025(49) Isotopic Composition = 0.0554(14) Standard Atomic Weight = 101.07(2) Notes = g Atomic Number = 44 Atomic Symbol = Ru Mass Number = 98 Relative Atomic Mass = 97.9052868(69) Isotopic Composition = 0.0187(3) Standard Atomic Weight = 101.07(2) Notes = g Atomic Number = 44 Atomic Symbol = Ru Mass Number = 99 Relative Atomic Mass = 98.9059341(11) Isotopic Composition = 0.1276(14) Standard Atomic Weight = 101.07(2) Notes = g Atomic Number = 44 Atomic Symbol = Ru Mass Number = 100 Relative Atomic Mass = 99.9042143(11) Isotopic Composition = 0.1260(7) Standard Atomic Weight = 101.07(2) Notes = g Atomic Number = 44 Atomic Symbol = Ru Mass Number = 101 Relative Atomic Mass = 100.9055769(12) Isotopic Composition = 0.1706(2) Standard Atomic Weight = 101.07(2) Notes = g Atomic Number = 44 Atomic Symbol = Ru Mass Number = 102 Relative Atomic Mass = 101.9043441(12) Isotopic Composition = 0.3155(14) Standard Atomic Weight = 101.07(2) Notes = g Atomic Number = 44 Atomic Symbol = Ru Mass Number = 104 Relative Atomic Mass = 103.9054275(28) Isotopic Composition = 0.1862(27) Standard Atomic Weight = 101.07(2) Notes = g Atomic Number = 45 Atomic Symbol = Rh Mass Number = 103 Relative Atomic Mass = 102.9054980(26) Isotopic Composition = 1 Standard Atomic Weight = 102.90550(2) Notes =   Atomic Number = 46 Atomic Symbol = Pd Mass Number = 102 Relative Atomic Mass = 101.9056022(28) Isotopic Composition = 0.0102(1) Standard Atomic Weight = 106.42(1) Notes = g Atomic Number = 46 Atomic Symbol = Pd Mass Number = 104 Relative Atomic Mass = 103.9040305(14) Isotopic Composition = 0.1114(8) Standard Atomic Weight = 106.42(1) Notes = g Atomic Number = 46 Atomic Symbol = Pd Mass Number = 105 Relative Atomic Mass = 104.9050796(12) Isotopic Composition = 0.2233(8) Standard Atomic Weight = 106.42(1) Notes = g Atomic Number = 46 Atomic Symbol = Pd Mass Number = 106 Relative Atomic Mass = 105.9034804(12) Isotopic Composition = 0.2733(3) Standard Atomic Weight = 106.42(1) Notes = g Atomic Number = 46 Atomic Symbol = Pd Mass Number = 108 Relative Atomic Mass = 107.9038916(12) Isotopic Composition = 0.2646(9) Standard Atomic Weight = 106.42(1) Notes = g Atomic Number = 46 Atomic Symbol = Pd Mass Number = 110 Relative Atomic Mass = 109.90517220(75) Isotopic Composition = 0.1172(9) Standard Atomic Weight = 106.42(1) Notes = g Atomic Number = 47 Atomic Symbol = Ag Mass Number = 107 Relative Atomic Mass = 106.9050916(26) Isotopic Composition = 0.51839(8) Standard Atomic Weight = 107.8682(2) Notes = g Atomic Number = 47 Atomic Symbol = Ag Mass Number = 109 Relative Atomic Mass = 108.9047553(14) Isotopic Composition = 0.48161(8) Standard Atomic Weight = 107.8682(2) Notes = g Atomic Number = 48 Atomic Symbol = Cd Mass Number = 106 Relative Atomic Mass = 105.9064599(12) Isotopic Composition = 0.0125(6) Standard Atomic Weight = 112.414(4) Notes = g Atomic Number = 48 Atomic Symbol = Cd Mass Number = 108 Relative Atomic Mass = 107.9041834(12) Isotopic Composition = 0.0089(3) Standard Atomic Weight = 112.414(4) Notes = g Atomic Number = 48 Atomic Symbol = Cd Mass Number = 110 Relative Atomic Mass = 109.90300661(61) Isotopic Composition = 0.1249(18) Standard Atomic Weight = 112.414(4) Notes = g Atomic Number = 48 Atomic Symbol = Cd Mass Number = 111 Relative Atomic Mass = 110.90418287(61) Isotopic Composition = 0.1280(12) Standard Atomic Weight = 112.414(4) Notes = g Atomic Number = 48 Atomic Symbol = Cd Mass Number = 112 Relative Atomic Mass = 111.90276287(60) Isotopic Composition = 0.2413(21) Standard Atomic Weight = 112.414(4) Notes = g Atomic Number = 48 Atomic Symbol = Cd Mass Number = 113 Relative Atomic Mass = 112.90440813(45) Isotopic Composition = 0.1222(12) Standard Atomic Weight = 112.414(4) Notes = g Atomic Number = 48 Atomic Symbol = Cd Mass Number = 114 Relative Atomic Mass = 113.90336509(43) Isotopic Composition = 0.2873(42) Standard Atomic Weight = 112.414(4) Notes = g Atomic Number = 48 Atomic Symbol = Cd Mass Number = 116 Relative Atomic Mass = 115.90476315(17) Isotopic Composition = 0.0749(18) Standard Atomic Weight = 112.414(4) Notes = g Atomic Number = 49 Atomic Symbol = In Mass Number = 113 Relative Atomic Mass = 112.90406184(91) Isotopic Composition = 0.0429(5) Standard Atomic Weight = 114.818(1) Notes =   Atomic Number = 49 Atomic Symbol = In Mass Number = 115 Relative Atomic Mass = 114.903878776(12) Isotopic Composition = 0.9571(5) Standard Atomic Weight = 114.818(1) Notes =   Atomic Number = 50 Atomic Symbol = Sn Mass Number = 112 Relative Atomic Mass = 111.90482387(61) Isotopic Composition = 0.0097(1) Standard Atomic Weight = 118.710(7) Notes = g Atomic Number = 50 Atomic Symbol = Sn Mass Number = 114 Relative Atomic Mass = 113.9027827(10) Isotopic Composition = 0.0066(1) Standard Atomic Weight = 118.710(7) Notes = g Atomic Number = 50 Atomic Symbol = Sn Mass Number = 115 Relative Atomic Mass = 114.903344699(16) Isotopic Composition = 0.0034(1) Standard Atomic Weight = 118.710(7) Notes = g Atomic Number = 50 Atomic Symbol = Sn Mass Number = 116 Relative Atomic Mass = 115.90174280(10) Isotopic Composition = 0.1454(9) Standard Atomic Weight = 118.710(7) Notes = g Atomic Number = 50 Atomic Symbol = Sn Mass Number = 117 Relative Atomic Mass = 116.90295398(52) Isotopic Composition = 0.0768(7) Standard Atomic Weight = 118.710(7) Notes = g Atomic Number = 50 Atomic Symbol = Sn Mass Number = 118 Relative Atomic Mass = 117.90160657(54) Isotopic Composition = 0.2422(9) Standard Atomic Weight = 118.710(7) Notes = g Atomic Number = 50 Atomic Symbol = Sn Mass Number = 119 Relative Atomic Mass = 118.90331117(78) Isotopic Composition = 0.0859(4) Standard Atomic Weight = 118.710(7) Notes = g Atomic Number = 50 Atomic Symbol = Sn Mass Number = 120 Relative Atomic Mass = 119.90220163(97) Isotopic Composition = 0.3258(9) Standard Atomic Weight = 118.710(7) Notes = g Atomic Number = 50 Atomic Symbol = Sn Mass Number = 122 Relative Atomic Mass = 121.9034438(26) Isotopic Composition = 0.0463(3) Standard Atomic Weight = 118.710(7) Notes = g Atomic Number = 50 Atomic Symbol = Sn Mass Number = 124 Relative Atomic Mass = 123.9052766(11) Isotopic Composition = 0.0579(5) Standard Atomic Weight = 118.710(7) Notes = g Atomic Number = 51 Atomic Symbol = Sb Mass Number = 121 Relative Atomic Mass = 120.9038120(30) Isotopic Composition = 0.5721(5) Standard Atomic Weight = 121.760(1) Notes = g Atomic Number = 51 Atomic Symbol = Sb Mass Number = 123 Relative Atomic Mass = 122.9042132(23) Isotopic Composition = 0.4279(5) Standard Atomic Weight = 121.760(1) Notes = g Atomic Number = 52 Atomic Symbol = Te Mass Number = 120 Relative Atomic Mass = 119.9040593(33) Isotopic Composition = 0.0009(1) Standard Atomic Weight = 127.60(3) Notes = g Atomic Number = 52 Atomic Symbol = Te Mass Number = 122 Relative Atomic Mass = 121.9030435(16) Isotopic Composition = 0.0255(12) Standard Atomic Weight = 127.60(3) Notes = g Atomic Number = 52 Atomic Symbol = Te Mass Number = 123 Relative Atomic Mass = 122.9042698(16) Isotopic Composition = 0.0089(3) Standard Atomic Weight = 127.60(3) Notes = g Atomic Number = 52 Atomic Symbol = Te Mass Number = 124 Relative Atomic Mass = 123.9028171(16) Isotopic Composition = 0.0474(14) Standard Atomic Weight = 127.60(3) Notes = g Atomic Number = 52 Atomic Symbol = Te Mass Number = 125 Relative Atomic Mass = 124.9044299(16) Isotopic Composition = 0.0707(15) Standard Atomic Weight = 127.60(3) Notes = g Atomic Number = 52 Atomic Symbol = Te Mass Number = 126 Relative Atomic Mass = 125.9033109(16) Isotopic Composition = 0.1884(25) Standard Atomic Weight = 127.60(3) Notes = g Atomic Number = 52 Atomic Symbol = Te Mass Number = 128 Relative Atomic Mass = 127.90446128(93) Isotopic Composition = 0.3174(8) Standard Atomic Weight = 127.60(3) Notes = g Atomic Number = 52 Atomic Symbol = Te Mass Number = 130 Relative Atomic Mass = 129.906222748(12) Isotopic Composition = 0.3408(62) Standard Atomic Weight = 127.60(3) Notes = g Atomic Number = 53 Atomic Symbol = I Mass Number = 127 Relative Atomic Mass = 126.9044719(39) Isotopic Composition = 1 Standard Atomic Weight = 126.90447(3) Notes =   Atomic Number = 54 Atomic Symbol = Xe Mass Number = 124 Relative Atomic Mass = 123.9058920(19) Isotopic Composition = 0.000952(3) Standard Atomic Weight = 131.293(6) Notes = g,m Atomic Number = 54 Atomic Symbol = Xe Mass Number = 126 Relative Atomic Mass = 125.9042983(38) Isotopic Composition = 0.000890(2) Standard Atomic Weight = 131.293(6) Notes = g,m Atomic Number = 54 Atomic Symbol = Xe Mass Number = 128 Relative Atomic Mass = 127.9035310(11) Isotopic Composition = 0.019102(8) Standard Atomic Weight = 131.293(6) Notes = g,m Atomic Number = 54 Atomic Symbol = Xe Mass Number = 129 Relative Atomic Mass = 128.9047808611(60) Isotopic Composition = 0.264006(82) Standard Atomic Weight = 131.293(6) Notes = g,m Atomic Number = 54 Atomic Symbol = Xe Mass Number = 130 Relative Atomic Mass = 129.903509349(10) Isotopic Composition = 0.040710(13) Standard Atomic Weight = 131.293(6) Notes = g,m Atomic Number = 54 Atomic Symbol = Xe Mass Number = 131 Relative Atomic Mass = 130.90508406(24) Isotopic Composition = 0.212324(30) Standard Atomic Weight = 131.293(6) Notes = g,m Atomic Number = 54 Atomic Symbol = Xe Mass Number = 132 Relative Atomic Mass = 131.9041550856(56) Isotopic Composition = 0.269086(33) Standard Atomic Weight = 131.293(6) Notes = g,m Atomic Number = 54 Atomic Symbol = Xe Mass Number = 134 Relative Atomic Mass = 133.90539466(90) Isotopic Composition = 0.104357(21) Standard Atomic Weight = 131.293(6) Notes = g,m Atomic Number = 54 Atomic Symbol = Xe Mass Number = 136 Relative Atomic Mass = 135.907214484(11) Isotopic Composition = 0.088573(44) Standard Atomic Weight = 131.293(6) Notes = g,m Atomic Number = 55 Atomic Symbol = Cs Mass Number = 133 Relative Atomic Mass = 132.9054519610(80) Isotopic Composition = 1 Standard Atomic Weight = 132.90545196(6) Notes =   Atomic Number = 56 Atomic Symbol = Ba Mass Number = 130 Relative Atomic Mass = 129.9063207(28) Isotopic Composition = 0.00106(1) Standard Atomic Weight = 137.327(7) Notes =   Atomic Number = 56 Atomic Symbol = Ba Mass Number = 132 Relative Atomic Mass = 131.9050611(11) Isotopic Composition = 0.00101(1) Standard Atomic Weight = 137.327(7) Notes =   Atomic Number = 56 Atomic Symbol = Ba Mass Number = 134 Relative Atomic Mass = 133.90450818(30) Isotopic Composition = 0.02417(18) Standard Atomic Weight = 137.327(7) Notes =   Atomic Number = 56 Atomic Symbol = Ba Mass Number = 135 Relative Atomic Mass = 134.90568838(29) Isotopic Composition = 0.06592(12) Standard Atomic Weight = 137.327(7) Notes =   Atomic Number = 56 Atomic Symbol = Ba Mass Number = 136 Relative Atomic Mass = 135.90457573(29) Isotopic Composition = 0.07854(24) Standard Atomic Weight = 137.327(7) Notes =   Atomic Number = 56 Atomic Symbol = Ba Mass Number = 137 Relative Atomic Mass = 136.90582714(30) Isotopic Composition = 0.11232(24) Standard Atomic Weight = 137.327(7) Notes =   Atomic Number = 56 Atomic Symbol = Ba Mass Number = 138 Relative Atomic Mass = 137.90524700(31) Isotopic Composition = 0.71698(42) Standard Atomic Weight = 137.327(7) Notes =   Atomic Number = 57 Atomic Symbol = La Mass Number = 138 Relative Atomic Mass = 137.9071149(37) Isotopic Composition = 0.0008881(71) Standard Atomic Weight = 138.90547(7) Notes = g Atomic Number = 57 Atomic Symbol = La Mass Number = 139 Relative Atomic Mass = 138.9063563(24) Isotopic Composition = 0.9991119(71) Standard Atomic Weight = 138.90547(7) Notes = g Atomic Number = 58 Atomic Symbol = Ce Mass Number = 136 Relative Atomic Mass = 135.90712921(41) Isotopic Composition = 0.00185(2) Standard Atomic Weight = 140.116(1) Notes = g Atomic Number = 58 Atomic Symbol = Ce Mass Number = 138 Relative Atomic Mass = 137.905991(11) Isotopic Composition = 0.00251(2) Standard Atomic Weight = 140.116(1) Notes = g Atomic Number = 58 Atomic Symbol = Ce Mass Number = 140 Relative Atomic Mass = 139.9054431(23) Isotopic Composition = 0.88450(51) Standard Atomic Weight = 140.116(1) Notes = g Atomic Number = 58 Atomic Symbol = Ce Mass Number = 142 Relative Atomic Mass = 141.9092504(29) Isotopic Composition = 0.11114(51) Standard Atomic Weight = 140.116(1) Notes = g Atomic Number = 59 Atomic Symbol = Pr Mass Number = 141 Relative Atomic Mass = 140.9076576(23) Isotopic Composition = 1 Standard Atomic Weight = 140.90766(2) Notes =   Atomic Number = 60 Atomic Symbol = Nd Mass Number = 142 Relative Atomic Mass = 141.9077290(20) Isotopic Composition = 0.27152(40) Standard Atomic Weight = 144.242(3) Notes = g Atomic Number = 60 Atomic Symbol = Nd Mass Number = 143 Relative Atomic Mass = 142.9098200(20) Isotopic Composition = 0.12174(26) Standard Atomic Weight = 144.242(3) Notes = g Atomic Number = 60 Atomic Symbol = Nd Mass Number = 144 Relative Atomic Mass = 143.9100930(20) Isotopic Composition = 0.23798(19) Standard Atomic Weight = 144.242(3) Notes = g Atomic Number = 60 Atomic Symbol = Nd Mass Number = 145 Relative Atomic Mass = 144.9125793(20) Isotopic Composition = 0.08293(12) Standard Atomic Weight = 144.242(3) Notes = g Atomic Number = 60 Atomic Symbol = Nd Mass Number = 146 Relative Atomic Mass = 145.9131226(20) Isotopic Composition = 0.17189(32) Standard Atomic Weight = 144.242(3) Notes = g Atomic Number = 60 Atomic Symbol = Nd Mass Number = 148 Relative Atomic Mass = 147.9168993(26) Isotopic Composition = 0.05756(21) Standard Atomic Weight = 144.242(3) Notes = g Atomic Number = 60 Atomic Symbol = Nd Mass Number = 150 Relative Atomic Mass = 149.9209022(18) Isotopic Composition = 0.05638(28) Standard Atomic Weight = 144.242(3) Notes = g Atomic Number = 61 Atomic Symbol = Pm Mass Number = 145 Relative Atomic Mass = 144.9127559(33) Isotopic Composition = Standard Atomic Weight = [145] Notes =   Atomic Number = 61 Atomic Symbol = Pm Mass Number = 147 Relative Atomic Mass = 146.9151450(19) Isotopic Composition = Standard Atomic Weight = [145] Notes =   Atomic Number = 62 Atomic Symbol = Sm Mass Number = 144 Relative Atomic Mass = 143.9120065(21) Isotopic Composition = 0.0307(7) Standard Atomic Weight = 150.36(2) Notes = g Atomic Number = 62 Atomic Symbol = Sm Mass Number = 147 Relative Atomic Mass = 146.9149044(19) Isotopic Composition = 0.1499(18) Standard Atomic Weight = 150.36(2) Notes = g Atomic Number = 62 Atomic Symbol = Sm Mass Number = 148 Relative Atomic Mass = 147.9148292(19) Isotopic Composition = 0.1124(10) Standard Atomic Weight = 150.36(2) Notes = g Atomic Number = 62 Atomic Symbol = Sm Mass Number = 149 Relative Atomic Mass = 148.9171921(18) Isotopic Composition = 0.1382(7) Standard Atomic Weight = 150.36(2) Notes = g Atomic Number = 62 Atomic Symbol = Sm Mass Number = 150 Relative Atomic Mass = 149.9172829(18) Isotopic Composition = 0.0738(1) Standard Atomic Weight = 150.36(2) Notes = g Atomic Number = 62 Atomic Symbol = Sm Mass Number = 152 Relative Atomic Mass = 151.9197397(18) Isotopic Composition = 0.2675(16) Standard Atomic Weight = 150.36(2) Notes = g Atomic Number = 62 Atomic Symbol = Sm Mass Number = 154 Relative Atomic Mass = 153.9222169(20) Isotopic Composition = 0.2275(29) Standard Atomic Weight = 150.36(2) Notes = g Atomic Number = 63 Atomic Symbol = Eu Mass Number = 151 Relative Atomic Mass = 150.9198578(18) Isotopic Composition = 0.4781(6) Standard Atomic Weight = 151.964(1) Notes = g Atomic Number = 63 Atomic Symbol = Eu Mass Number = 153 Relative Atomic Mass = 152.9212380(18) Isotopic Composition = 0.5219(6) Standard Atomic Weight = 151.964(1) Notes = g Atomic Number = 64 Atomic Symbol = Gd Mass Number = 152 Relative Atomic Mass = 151.9197995(18) Isotopic Composition = 0.0020(1) Standard Atomic Weight = 157.25(3) Notes = g Atomic Number = 64 Atomic Symbol = Gd Mass Number = 154 Relative Atomic Mass = 153.9208741(17) Isotopic Composition = 0.0218(3) Standard Atomic Weight = 157.25(3) Notes = g Atomic Number = 64 Atomic Symbol = Gd Mass Number = 155 Relative Atomic Mass = 154.9226305(17) Isotopic Composition = 0.1480(12) Standard Atomic Weight = 157.25(3) Notes = g Atomic Number = 64 Atomic Symbol = Gd Mass Number = 156 Relative Atomic Mass = 155.9221312(17) Isotopic Composition = 0.2047(9) Standard Atomic Weight = 157.25(3) Notes = g Atomic Number = 64 Atomic Symbol = Gd Mass Number = 157 Relative Atomic Mass = 156.9239686(17) Isotopic Composition = 0.1565(2) Standard Atomic Weight = 157.25(3) Notes = g Atomic Number = 64 Atomic Symbol = Gd Mass Number = 158 Relative Atomic Mass = 157.9241123(17) Isotopic Composition = 0.2484(7) Standard Atomic Weight = 157.25(3) Notes = g Atomic Number = 64 Atomic Symbol = Gd Mass Number = 160 Relative Atomic Mass = 159.9270624(18) Isotopic Composition = 0.2186(19) Standard Atomic Weight = 157.25(3) Notes = g Atomic Number = 65 Atomic Symbol = Tb Mass Number = 159 Relative Atomic Mass = 158.9253547(19) Isotopic Composition = 1 Standard Atomic Weight = 158.92535(2) Notes =   Atomic Number = 66 Atomic Symbol = Dy Mass Number = 156 Relative Atomic Mass = 155.9242847(17) Isotopic Composition = 0.00056(3) Standard Atomic Weight = 162.500(1) Notes = g Atomic Number = 66 Atomic Symbol = Dy Mass Number = 158 Relative Atomic Mass = 157.9244159(31) Isotopic Composition = 0.00095(3) Standard Atomic Weight = 162.500(1) Notes = g Atomic Number = 66 Atomic Symbol = Dy Mass Number = 160 Relative Atomic Mass = 159.9252046(20) Isotopic Composition = 0.02329(18) Standard Atomic Weight = 162.500(1) Notes = g Atomic Number = 66 Atomic Symbol = Dy Mass Number = 161 Relative Atomic Mass = 160.9269405(20) Isotopic Composition = 0.18889(42) Standard Atomic Weight = 162.500(1) Notes = g Atomic Number = 66 Atomic Symbol = Dy Mass Number = 162 Relative Atomic Mass = 161.9268056(20) Isotopic Composition = 0.25475(36) Standard Atomic Weight = 162.500(1) Notes = g Atomic Number = 66 Atomic Symbol = Dy Mass Number = 163 Relative Atomic Mass = 162.9287383(20) Isotopic Composition = 0.24896(42) Standard Atomic Weight = 162.500(1) Notes = g Atomic Number = 66 Atomic Symbol = Dy Mass Number = 164 Relative Atomic Mass = 163.9291819(20) Isotopic Composition = 0.28260(54) Standard Atomic Weight = 162.500(1) Notes = g Atomic Number = 67 Atomic Symbol = Ho Mass Number = 165 Relative Atomic Mass = 164.9303288(21) Isotopic Composition = 1 Standard Atomic Weight = 164.93033(2) Notes =   Atomic Number = 68 Atomic Symbol = Er Mass Number = 162 Relative Atomic Mass = 161.9287884(20) Isotopic Composition = 0.00139(5) Standard Atomic Weight = 167.259(3) Notes = g Atomic Number = 68 Atomic Symbol = Er Mass Number = 164 Relative Atomic Mass = 163.9292088(20) Isotopic Composition = 0.01601(3) Standard Atomic Weight = 167.259(3) Notes = g Atomic Number = 68 Atomic Symbol = Er Mass Number = 166 Relative Atomic Mass = 165.9302995(22) Isotopic Composition = 0.33503(36) Standard Atomic Weight = 167.259(3) Notes = g Atomic Number = 68 Atomic Symbol = Er Mass Number = 167 Relative Atomic Mass = 166.9320546(22) Isotopic Composition = 0.22869(9) Standard Atomic Weight = 167.259(3) Notes = g Atomic Number = 68 Atomic Symbol = Er Mass Number = 168 Relative Atomic Mass = 167.9323767(22) Isotopic Composition = 0.26978(18) Standard Atomic Weight = 167.259(3) Notes = g Atomic Number = 68 Atomic Symbol = Er Mass Number = 170 Relative Atomic Mass = 169.9354702(26) Isotopic Composition = 0.14910(36) Standard Atomic Weight = 167.259(3) Notes = g Atomic Number = 69 Atomic Symbol = Tm Mass Number = 169 Relative Atomic Mass = 168.9342179(22) Isotopic Composition = 1 Standard Atomic Weight = 168.93422(2) Notes =   Atomic Number = 70 Atomic Symbol = Yb Mass Number = 168 Relative Atomic Mass = 167.9338896(22) Isotopic Composition = 0.00123(3) Standard Atomic Weight = 173.054(5) Notes = g Atomic Number = 70 Atomic Symbol = Yb Mass Number = 170 Relative Atomic Mass = 169.9347664(22) Isotopic Composition = 0.02982(39) Standard Atomic Weight = 173.054(5) Notes = g Atomic Number = 70 Atomic Symbol = Yb Mass Number = 171 Relative Atomic Mass = 170.9363302(22) Isotopic Composition = 0.1409(14) Standard Atomic Weight = 173.054(5) Notes = g Atomic Number = 70 Atomic Symbol = Yb Mass Number = 172 Relative Atomic Mass = 171.9363859(22) Isotopic Composition = 0.2168(13) Standard Atomic Weight = 173.054(5) Notes = g Atomic Number = 70 Atomic Symbol = Yb Mass Number = 173 Relative Atomic Mass = 172.9382151(22) Isotopic Composition = 0.16103(63) Standard Atomic Weight = 173.054(5) Notes = g Atomic Number = 70 Atomic Symbol = Yb Mass Number = 174 Relative Atomic Mass = 173.9388664(22) Isotopic Composition = 0.32026(80) Standard Atomic Weight = 173.054(5) Notes = g Atomic Number = 70 Atomic Symbol = Yb Mass Number = 176 Relative Atomic Mass = 175.9425764(24) Isotopic Composition = 0.12996(83) Standard Atomic Weight = 173.054(5) Notes = g Atomic Number = 71 Atomic Symbol = Lu Mass Number = 175 Relative Atomic Mass = 174.9407752(20) Isotopic Composition = 0.97401(13) Standard Atomic Weight = 174.9668(1) Notes = g Atomic Number = 71 Atomic Symbol = Lu Mass Number = 176 Relative Atomic Mass = 175.9426897(20) Isotopic Composition = 0.02599(13) Standard Atomic Weight = 174.9668(1) Notes = g Atomic Number = 72 Atomic Symbol = Hf Mass Number = 174 Relative Atomic Mass = 173.9400461(28) Isotopic Composition = 0.0016(1) Standard Atomic Weight = 178.49(2) Notes =   Atomic Number = 72 Atomic Symbol = Hf Mass Number = 176 Relative Atomic Mass = 175.9414076(22) Isotopic Composition = 0.0526(7) Standard Atomic Weight = 178.49(2) Notes =   Atomic Number = 72 Atomic Symbol = Hf Mass Number = 177 Relative Atomic Mass = 176.9432277(20) Isotopic Composition = 0.1860(9) Standard Atomic Weight = 178.49(2) Notes =   Atomic Number = 72 Atomic Symbol = Hf Mass Number = 178 Relative Atomic Mass = 177.9437058(20) Isotopic Composition = 0.2728(7) Standard Atomic Weight = 178.49(2) Notes =   Atomic Number = 72 Atomic Symbol = Hf Mass Number = 179 Relative Atomic Mass = 178.9458232(20) Isotopic Composition = 0.1362(2) Standard Atomic Weight = 178.49(2) Notes =   Atomic Number = 72 Atomic Symbol = Hf Mass Number = 180 Relative Atomic Mass = 179.9465570(20) Isotopic Composition = 0.3508(16) Standard Atomic Weight = 178.49(2) Notes =   Atomic Number = 73 Atomic Symbol = Ta Mass Number = 180 Relative Atomic Mass = 179.9474648(24) Isotopic Composition = 0.0001201(32) Standard Atomic Weight = 180.94788(2) Notes =   Atomic Number = 73 Atomic Symbol = Ta Mass Number = 181 Relative Atomic Mass = 180.9479958(20) Isotopic Composition = 0.9998799(32) Standard Atomic Weight = 180.94788(2) Notes =   Atomic Number = 74 Atomic Symbol = W Mass Number = 180 Relative Atomic Mass = 179.9467108(20) Isotopic Composition = 0.0012(1) Standard Atomic Weight = 183.84(1) Notes =   Atomic Number = 74 Atomic Symbol = W Mass Number = 182 Relative Atomic Mass = 181.94820394(91) Isotopic Composition = 0.2650(16) Standard Atomic Weight = 183.84(1) Notes =   Atomic Number = 74 Atomic Symbol = W Mass Number = 183 Relative Atomic Mass = 182.95022275(90) Isotopic Composition = 0.1431(4) Standard Atomic Weight = 183.84(1) Notes =   Atomic Number = 74 Atomic Symbol = W Mass Number = 184 Relative Atomic Mass = 183.95093092(94) Isotopic Composition = 0.3064(2) Standard Atomic Weight = 183.84(1) Notes =   Atomic Number = 74 Atomic Symbol = W Mass Number = 186 Relative Atomic Mass = 185.9543628(17) Isotopic Composition = 0.2843(19) Standard Atomic Weight = 183.84(1) Notes =   Atomic Number = 75 Atomic Symbol = Re Mass Number = 185 Relative Atomic Mass = 184.9529545(13) Isotopic Composition = 0.3740(2) Standard Atomic Weight = 186.207(1) Notes =   Atomic Number = 75 Atomic Symbol = Re Mass Number = 187 Relative Atomic Mass = 186.9557501(16) Isotopic Composition = 0.6260(2) Standard Atomic Weight = 186.207(1) Notes =   Atomic Number = 76 Atomic Symbol = Os Mass Number = 184 Relative Atomic Mass = 183.9524885(14) Isotopic Composition = 0.0002(1) Standard Atomic Weight = 190.23(3) Notes = g Atomic Number = 76 Atomic Symbol = Os Mass Number = 186 Relative Atomic Mass = 185.9538350(16) Isotopic Composition = 0.0159(3) Standard Atomic Weight = 190.23(3) Notes = g Atomic Number = 76 Atomic Symbol = Os Mass Number = 187 Relative Atomic Mass = 186.9557474(16) Isotopic Composition = 0.0196(2) Standard Atomic Weight = 190.23(3) Notes = g Atomic Number = 76 Atomic Symbol = Os Mass Number = 188 Relative Atomic Mass = 187.9558352(16) Isotopic Composition = 0.1324(8) Standard Atomic Weight = 190.23(3) Notes = g Atomic Number = 76 Atomic Symbol = Os Mass Number = 189 Relative Atomic Mass = 188.9581442(17) Isotopic Composition = 0.1615(5) Standard Atomic Weight = 190.23(3) Notes = g Atomic Number = 76 Atomic Symbol = Os Mass Number = 190 Relative Atomic Mass = 189.9584437(17) Isotopic Composition = 0.2626(2) Standard Atomic Weight = 190.23(3) Notes = g Atomic Number = 76 Atomic Symbol = Os Mass Number = 192 Relative Atomic Mass = 191.9614770(29) Isotopic Composition = 0.4078(19) Standard Atomic Weight = 190.23(3) Notes = g Atomic Number = 77 Atomic Symbol = Ir Mass Number = 191 Relative Atomic Mass = 190.9605893(21) Isotopic Composition = 0.373(2) Standard Atomic Weight = 192.217(3) Notes =   Atomic Number = 77 Atomic Symbol = Ir Mass Number = 193 Relative Atomic Mass = 192.9629216(21) Isotopic Composition = 0.627(2) Standard Atomic Weight = 192.217(3) Notes =   Atomic Number = 78 Atomic Symbol = Pt Mass Number = 190 Relative Atomic Mass = 189.9599297(63) Isotopic Composition = 0.00012(2) Standard Atomic Weight = 195.084(9) Notes =   Atomic Number = 78 Atomic Symbol = Pt Mass Number = 192 Relative Atomic Mass = 191.9610387(32) Isotopic Composition = 0.00782(24) Standard Atomic Weight = 195.084(9) Notes =   Atomic Number = 78 Atomic Symbol = Pt Mass Number = 194 Relative Atomic Mass = 193.9626809(10) Isotopic Composition = 0.3286(40) Standard Atomic Weight = 195.084(9) Notes =   Atomic Number = 78 Atomic Symbol = Pt Mass Number = 195 Relative Atomic Mass = 194.9647917(10) Isotopic Composition = 0.3378(24) Standard Atomic Weight = 195.084(9) Notes =   Atomic Number = 78 Atomic Symbol = Pt Mass Number = 196 Relative Atomic Mass = 195.96495209(99) Isotopic Composition = 0.2521(34) Standard Atomic Weight = 195.084(9) Notes =   Atomic Number = 78 Atomic Symbol = Pt Mass Number = 198 Relative Atomic Mass = 197.9678949(23) Isotopic Composition = 0.07356(130) Standard Atomic Weight = 195.084(9) Notes =   Atomic Number = 79 Atomic Symbol = Au Mass Number = 197 Relative Atomic Mass = 196.96656879(71) Isotopic Composition = 1 Standard Atomic Weight = 196.966569(5) Notes =   Atomic Number = 80 Atomic Symbol = Hg Mass Number = 196 Relative Atomic Mass = 195.9658326(32) Isotopic Composition = 0.0015(1) Standard Atomic Weight = 200.592(3) Notes =   Atomic Number = 80 Atomic Symbol = Hg Mass Number = 198 Relative Atomic Mass = 197.96676860(52) Isotopic Composition = 0.0997(20) Standard Atomic Weight = 200.592(3) Notes =   Atomic Number = 80 Atomic Symbol = Hg Mass Number = 199 Relative Atomic Mass = 198.96828064(46) Isotopic Composition = 0.1687(22) Standard Atomic Weight = 200.592(3) Notes =   Atomic Number = 80 Atomic Symbol = Hg Mass Number = 200 Relative Atomic Mass = 199.96832659(47) Isotopic Composition = 0.2310(19) Standard Atomic Weight = 200.592(3) Notes =   Atomic Number = 80 Atomic Symbol = Hg Mass Number = 201 Relative Atomic Mass = 200.97030284(69) Isotopic Composition = 0.1318(9) Standard Atomic Weight = 200.592(3) Notes =   Atomic Number = 80 Atomic Symbol = Hg Mass Number = 202 Relative Atomic Mass = 201.97064340(69) Isotopic Composition = 0.2986(26) Standard Atomic Weight = 200.592(3) Notes =   Atomic Number = 80 Atomic Symbol = Hg Mass Number = 204 Relative Atomic Mass = 203.97349398(53) Isotopic Composition = 0.0687(15) Standard Atomic Weight = 200.592(3) Notes =   Atomic Number = 81 Atomic Symbol = Tl Mass Number = 203 Relative Atomic Mass = 202.9723446(14) Isotopic Composition = 0.2952(1) Standard Atomic Weight = [204.382,204.385] Notes =   Atomic Number = 81 Atomic Symbol = Tl Mass Number = 205 Relative Atomic Mass = 204.9744278(14) Isotopic Composition = 0.7048(1) Standard Atomic Weight = [204.382,204.385] Notes =   Atomic Number = 82 Atomic Symbol = Pb Mass Number = 204 Relative Atomic Mass = 203.9730440(13) Isotopic Composition = 0.014(1) Standard Atomic Weight = 207.2(1) Notes = g,r Atomic Number = 82 Atomic Symbol = Pb Mass Number = 206 Relative Atomic Mass = 205.9744657(13) Isotopic Composition = 0.241(1) Standard Atomic Weight = 207.2(1) Notes = g,r Atomic Number = 82 Atomic Symbol = Pb Mass Number = 207 Relative Atomic Mass = 206.9758973(13) Isotopic Composition = 0.221(1) Standard Atomic Weight = 207.2(1) Notes = g,r Atomic Number = 82 Atomic Symbol = Pb Mass Number = 208 Relative Atomic Mass = 207.9766525(13) Isotopic Composition = 0.524(1) Standard Atomic Weight = 207.2(1) Notes = g,r Atomic Number = 83 Atomic Symbol = Bi Mass Number = 209 Relative Atomic Mass = 208.9803991(16) Isotopic Composition = 1 Standard Atomic Weight = 208.98040(1) Notes =   Atomic Number = 84 Atomic Symbol = Po Mass Number = 209 Relative Atomic Mass = 208.9824308(20) Isotopic Composition = Standard Atomic Weight = [209] Notes =   Atomic Number = 84 Atomic Symbol = Po Mass Number = 210 Relative Atomic Mass = 209.9828741(13) Isotopic Composition = Standard Atomic Weight = [209] Notes =   Atomic Number = 85 Atomic Symbol = At Mass Number = 210 Relative Atomic Mass = 209.9871479(83) Isotopic Composition = Standard Atomic Weight = [210] Notes =   Atomic Number = 85 Atomic Symbol = At Mass Number = 211 Relative Atomic Mass = 210.9874966(30) Isotopic Composition = Standard Atomic Weight = [210] Notes =   Atomic Number = 86 Atomic Symbol = Rn Mass Number = 211 Relative Atomic Mass = 210.9906011(73) Isotopic Composition = Standard Atomic Weight = [222] Notes =   Atomic Number = 86 Atomic Symbol = Rn Mass Number = 220 Relative Atomic Mass = 220.0113941(23) Isotopic Composition = Standard Atomic Weight = [222] Notes =   Atomic Number = 86 Atomic Symbol = Rn Mass Number = 222 Relative Atomic Mass = 222.0175782(25) Isotopic Composition = Standard Atomic Weight = [222] Notes =   Atomic Number = 87 Atomic Symbol = Fr Mass Number = 223 Relative Atomic Mass = 223.0197360(25) Isotopic Composition = Standard Atomic Weight = [223] Notes =   Atomic Number = 88 Atomic Symbol = Ra Mass Number = 223 Relative Atomic Mass = 223.0185023(27) Isotopic Composition = Standard Atomic Weight = [226] Notes =   Atomic Number = 88 Atomic Symbol = Ra Mass Number = 224 Relative Atomic Mass = 224.0202120(23) Isotopic Composition = Standard Atomic Weight = [226] Notes =   Atomic Number = 88 Atomic Symbol = Ra Mass Number = 226 Relative Atomic Mass = 226.0254103(25) Isotopic Composition = Standard Atomic Weight = [226] Notes =   Atomic Number = 88 Atomic Symbol = Ra Mass Number = 228 Relative Atomic Mass = 228.0310707(26) Isotopic Composition = Standard Atomic Weight = [226] Notes =   Atomic Number = 89 Atomic Symbol = Ac Mass Number = 227 Relative Atomic Mass = 227.0277523(25) Isotopic Composition = Standard Atomic Weight = [227] Notes =   Atomic Number = 90 Atomic Symbol = Th Mass Number = 230 Relative Atomic Mass = 230.0331341(19) Isotopic Composition = Standard Atomic Weight = 232.0377(4) Notes = g Atomic Number = 90 Atomic Symbol = Th Mass Number = 232 Relative Atomic Mass = 232.0380558(21) Isotopic Composition = 1 Standard Atomic Weight = 232.0377(4) Notes = g Atomic Number = 91 Atomic Symbol = Pa Mass Number = 231 Relative Atomic Mass = 231.0358842(24) Isotopic Composition = 1 Standard Atomic Weight = 231.03588(2) Notes =   Atomic Number = 92 Atomic Symbol = U Mass Number = 233 Relative Atomic Mass = 233.0396355(29) Isotopic Composition = Standard Atomic Weight = 238.02891(3) Notes = g,m Atomic Number = 92 Atomic Symbol = U Mass Number = 234 Relative Atomic Mass = 234.0409523(19) Isotopic Composition = 0.000054(5) Standard Atomic Weight = 238.02891(3) Notes = g,m Atomic Number = 92 Atomic Symbol = U Mass Number = 235 Relative Atomic Mass = 235.0439301(19) Isotopic Composition = 0.007204(6) Standard Atomic Weight = 238.02891(3) Notes = g,m Atomic Number = 92 Atomic Symbol = U Mass Number = 236 Relative Atomic Mass = 236.0455682(19) Isotopic Composition = Standard Atomic Weight = 238.02891(3) Notes = g,m Atomic Number = 92 Atomic Symbol = U Mass Number = 238 Relative Atomic Mass = 238.0507884(20) Isotopic Composition = 0.992742(10) Standard Atomic Weight = 238.02891(3) Notes = g,m Atomic Number = 93 Atomic Symbol = Np Mass Number = 236 Relative Atomic Mass = 236.046570(54) Isotopic Composition = Standard Atomic Weight = [237] Notes =   Atomic Number = 93 Atomic Symbol = Np Mass Number = 237 Relative Atomic Mass = 237.0481736(19) Isotopic Composition = Standard Atomic Weight = [237] Notes =   Atomic Number = 94 Atomic Symbol = Pu Mass Number = 238 Relative Atomic Mass = 238.0495601(19) Isotopic Composition = Standard Atomic Weight = [244] Notes =   Atomic Number = 94 Atomic Symbol = Pu Mass Number = 239 Relative Atomic Mass = 239.0521636(19) Isotopic Composition = Standard Atomic Weight = [244] Notes =   Atomic Number = 94 Atomic Symbol = Pu Mass Number = 240 Relative Atomic Mass = 240.0538138(19) Isotopic Composition = Standard Atomic Weight = [244] Notes =   Atomic Number = 94 Atomic Symbol = Pu Mass Number = 241 Relative Atomic Mass = 241.0568517(19) Isotopic Composition = Standard Atomic Weight = [244] Notes =   Atomic Number = 94 Atomic Symbol = Pu Mass Number = 242 Relative Atomic Mass = 242.0587428(20) Isotopic Composition = Standard Atomic Weight = [244] Notes =   Atomic Number = 94 Atomic Symbol = Pu Mass Number = 244 Relative Atomic Mass = 244.0642053(56) Isotopic Composition = Standard Atomic Weight = [244] Notes =   Atomic Number = 95 Atomic Symbol = Am Mass Number = 241 Relative Atomic Mass = 241.0568293(19) Isotopic Composition = Standard Atomic Weight =   Notes =   Atomic Number = 95 Atomic Symbol = Am Mass Number = 243 Relative Atomic Mass = 243.0613813(24) Isotopic Composition = Standard Atomic Weight =   Notes =   Atomic Number = 96 Atomic Symbol = Cm Mass Number = 243 Relative Atomic Mass = 243.0613893(22) Isotopic Composition = Standard Atomic Weight =   Notes =   Atomic Number = 96 Atomic Symbol = Cm Mass Number = 244 Relative Atomic Mass = 244.0627528(19) Isotopic Composition = Standard Atomic Weight =   Notes =   Atomic Number = 96 Atomic Symbol = Cm Mass Number = 245 Relative Atomic Mass = 245.0654915(22) Isotopic Composition = Standard Atomic Weight =   Notes =   Atomic Number = 96 Atomic Symbol = Cm Mass Number = 246 Relative Atomic Mass = 246.0672238(22) Isotopic Composition = Standard Atomic Weight =   Notes =   Atomic Number = 96 Atomic Symbol = Cm Mass Number = 247 Relative Atomic Mass = 247.0703541(47) Isotopic Composition = Standard Atomic Weight =   Notes =   Atomic Number = 96 Atomic Symbol = Cm Mass Number = 248 Relative Atomic Mass = 248.0723499(56) Isotopic Composition = Standard Atomic Weight =   Notes =   Atomic Number = 97 Atomic Symbol = Bk Mass Number = 247 Relative Atomic Mass = 247.0703073(59) Isotopic Composition = Standard Atomic Weight =   Notes =   Atomic Number = 97 Atomic Symbol = Bk Mass Number = 249 Relative Atomic Mass = 249.0749877(27) Isotopic Composition = Standard Atomic Weight =   Notes =   Atomic Number = 98 Atomic Symbol = Cf Mass Number = 249 Relative Atomic Mass = 249.0748539(23) Isotopic Composition = Standard Atomic Weight =   Notes =   Atomic Number = 98 Atomic Symbol = Cf Mass Number = 250 Relative Atomic Mass = 250.0764062(22) Isotopic Composition = Standard Atomic Weight =   Notes =   Atomic Number = 98 Atomic Symbol = Cf Mass Number = 251 Relative Atomic Mass = 251.0795886(48) Isotopic Composition = Standard Atomic Weight =   Notes =   Atomic Number = 98 Atomic Symbol = Cf Mass Number = 252 Relative Atomic Mass = 252.0816272(56) Isotopic Composition = Standard Atomic Weight =   Notes =   Atomic Number = 99 Atomic Symbol = Es Mass Number = 252 Relative Atomic Mass = 252.082980(54) Isotopic Composition = Standard Atomic Weight =   Notes =   Atomic Number = 100 Atomic Symbol = Fm Mass Number = 257 Relative Atomic Mass = 257.0951061(69) Isotopic Composition = Standard Atomic Weight =   Notes =   Atomic Number = 101 Atomic Symbol = Md Mass Number = 258 Relative Atomic Mass = 258.0984315(50) Isotopic Composition = Standard Atomic Weight =   Notes =   Atomic Number = 101 Atomic Symbol = Md Mass Number = 260 Relative Atomic Mass = 260.10365(34#) Isotopic Composition = Standard Atomic Weight =   Notes =   Atomic Number = 102 Atomic Symbol = No Mass Number = 259 Relative Atomic Mass = 259.10103(11#) Isotopic Composition = Standard Atomic Weight =   Notes =   Atomic Number = 103 Atomic Symbol = Lr Mass Number = 262 Relative Atomic Mass = 262.10961(22#) Isotopic Composition = Standard Atomic Weight =   Notes =   Atomic Number = 104 Atomic Symbol = Rf Mass Number = 267 Relative Atomic Mass = 267.12179(62#) Isotopic Composition = Standard Atomic Weight =   Notes =   Atomic Number = 105 Atomic Symbol = Db Mass Number = 268 Relative Atomic Mass = 268.12567(57#) Isotopic Composition = Standard Atomic Weight =   Notes =   Atomic Number = 106 Atomic Symbol = Sg Mass Number = 271 Relative Atomic Mass = 271.13393(63#) Isotopic Composition = Standard Atomic Weight =   Notes =   Atomic Number = 107 Atomic Symbol = Bh Mass Number = 272 Relative Atomic Mass = 272.13826(58#) Isotopic Composition = Standard Atomic Weight =   Notes =   Atomic Number = 108 Atomic Symbol = Hs Mass Number = 270 Relative Atomic Mass = 270.13429(27#) Isotopic Composition = Standard Atomic Weight =   Notes =   Atomic Number = 109 Atomic Symbol = Mt Mass Number = 276 Relative Atomic Mass = 276.15159(59#) Isotopic Composition = Standard Atomic Weight =   Notes =   Atomic Number = 110 Atomic Symbol = Ds Mass Number = 281 Relative Atomic Mass = 281.16451(59#) Isotopic Composition = Standard Atomic Weight =   Notes =   Atomic Number = 111 Atomic Symbol = Rg Mass Number = 280 Relative Atomic Mass = 280.16514(61#) Isotopic Composition = Standard Atomic Weight =   Notes =   Atomic Number = 112 Atomic Symbol = Cn Mass Number = 285 Relative Atomic Mass = 285.17712(60#) Isotopic Composition = Standard Atomic Weight =   Notes =   Atomic Number = 113 Atomic Symbol = Nh Mass Number = 284 Relative Atomic Mass = 284.17873(62#) Isotopic Composition = Standard Atomic Weight =   Notes =   Atomic Number = 114 Atomic Symbol = Fl Mass Number = 289 Relative Atomic Mass = 289.19042(60#) Isotopic Composition = Standard Atomic Weight =   Notes =   Atomic Number = 115 Atomic Symbol = Mc Mass Number = 288 Relative Atomic Mass = 288.19274(62#) Isotopic Composition = Standard Atomic Weight =   Notes =   Atomic Number = 116 Atomic Symbol = Lv Mass Number = 293 Relative Atomic Mass = 293.20449(60#) Isotopic Composition = Standard Atomic Weight =   Notes =   Atomic Number = 117 Atomic Symbol = Ts Mass Number = 292 Relative Atomic Mass = 292.20746(75#) Isotopic Composition = Standard Atomic Weight =   Notes =   Atomic Number = 118 Atomic Symbol = Og Mass Number = 294 Relative Atomic Mass = 294.21392(71#) Isotopic Composition = Standard Atomic Weight =   Notes =