Cs
Caesium
Z 55 132.905 g/molAlkali Metal
| 133Cs | 78 | 132.9055 | -88,070.943 | 100.0% | Stable | 7/2+ | --- | 1921 |
| 111Cs | 56 | 110.9539 | -42,900.0 | --- | 1.0 µs | (3/2+) | p→110Xe | --- |
| 112Cs | 57 | 111.9502 | -46,420.0 | --- | 490.0 µs | (1+) | p→111Xe(~100%) α→108I(<0.26%) | 1994 |
| 113Cs | 58 | 112.9444 | -51,765.0 | --- | 16.94 µs | (3/2+) | p→112Xe(100%) | 1984 |
| 114Cs | 59 | 113.9413 | -54,690.0 | --- | 570.0 ms | (1+) | β⁺→114Xe(91.11%) β⁺p→113I(8.7%) β⁺α→110Te(0.19%) α→110I(0.018%) | 1978 |
| 115Cs | 60 | 114.9359 | -59,700.0 | --- | 1.4 s | (9/2+) | β⁺→115Xe(99.93%) β⁺p→114I(0.07%) | 1978 |
| 116Cs | 61 | 115.9334 | -62,040.0 | --- | 700.0 ms | (1+) | β⁺→116Xe(99.671%) β⁺p→115I(0.28%) β⁺α→112Te(0.049%) | 1975 |
| 116mCs | 61 | 115.9335 | -61,940.0 | --- | 3.85 s | (7+) | β⁺→116Xe(99.557%) β⁺p→115I(0.44%) β⁺α→112Te(0.003%) | 1975 |
| 117Cs | 62 | 116.9286 | -66,490.0 | --- | 8.4 s | (9/2+) | β⁺→117Xe(100%) | 1972 |
| 117mCs | 62 | 116.9288 | -66,340.0 | --- | 6.5 s | (3/2+) | β⁺→117Xe(100%) | 1978 |
| 118Cs | 63 | 117.9266 | -68,409.0 | --- | 14.0 s | 2+ | β⁺→118Xe(99.978%) β⁺p→117I(0.021%) β⁺α→114Te(0.001%) | 1969 |
| 118mCs | 63 | 117.9267 | -68,310.0 | --- | 17.0 s | (7-) | β⁺→118Xe(99.978%) β⁺p→117I(0.021%) β⁺α→114Te(0.001%) | 1972 |
| 119Cs | 64 | 118.9224 | -72,305.0 | --- | 43.0 s | 9/2+ | β⁺→119Xe(~100%) β⁺α→115Te(<2e-6%) | 1969 |
| 119mCs | 64 | 118.9224 | -72,260.0 | --- | 30.4 s | 3/2+ | β⁺→119Xe(100%) | 1978 |
| 120Cs | 65 | 119.9207 | -73,889.0 | --- | 1.01 m | 2+ | β⁺→120Xe(~100%) β⁺α→116Te(<2e-5%) β⁺p→119I(<7e-6%) | 1969 |
| 120mCs | 65 | 119.9208 | -73,790.0 | --- | 57.0 s | (7-) | β⁺→120Xe(~100%) β⁺α→116Te(<2e-5%) β⁺p→119I(<7e-6%) | 1977 |
| 121Cs | 66 | 120.9172 | -77,102.0 | --- | 2.58 m | 3/2+ | β⁺→121Xe(100%) | 1969 |
| 121mCs | 66 | 120.9173 | -77,034.0 | --- | 2.03 m | 9/2+ | β⁺→121Xe(83%) γ→121Cs(17%) | 1981 |
| 122Cs | 67 | 121.9161 | -78,140.0 | --- | 21.18 s | 1+ | β⁺→122Xe(~100%) β⁺α→118Te(<2e-7%) | 1969 |
| 122mCs | 67 | 121.9162 | -78,090.0 | --- | --- | 3+ | γ→122Cs(100%) | 1987 |
| 122nCs | 67 | 121.9163 | -78,005.0 | --- | 3.7 m | 8- | β⁺→122Xe(100%) | 1969 |
| 123Cs | 68 | 122.913 | -81,044.0 | --- | 5.88 m | 1/2+ | β⁺→123Xe(100%) | 1954 |
| 123mCs | 68 | 122.9132 | -80,888.0 | --- | 1.64 s | 11/2- | γ→123Cs(100%) | 1972 |
| 123nCs | 68 | 122.9133 | -80,792.0 | --- | 114.0 ns | (9/2+) | γ→123Cs(100%) | 2000 |
| 124Cs | 69 | 123.9122 | -81,741.0 | --- | 30.9 s | 1+ | β⁺→124Xe(100%) | 1969 |
| 124mCs | 69 | 123.9127 | -81,278.0 | --- | 6.41 s | (7+) | γ→124Cs(99.89%) β⁺→124Xe(0.11%) | 1983 |
| 125Cs | 70 | 124.9097 | -84,090.0 | --- | 44.35 m | 1/2+ | β⁺→125Xe(100%) | 1954 |
| 125mCs | 70 | 124.91 | -83,824.0 | --- | 900.0 µs | (11/2-) | γ→125Cs(100%) | 1998 |
| 126Cs | 71 | 125.9094 | -84,351.0 | --- | 1.64 m | 1+ | β⁺→126Xe(100%) | 1954 |
| 126mCs | 71 | 125.9097 | -84,078.0 | --- | --- | (4-) | γ→126Cs(100%) | 1993 |
| 126nCs | 71 | 125.9101 | -83,755.0 | --- | 171.0 µs | (8-) | γ→126Cs(100%) | 1993 |
| 127Cs | 72 | 126.9074 | -86,240.0 | --- | 6.25 h | 1/2+ | β⁺→127Xe(100%) | 1950 |
| 127mCs | 72 | 126.9079 | -85,788.0 | --- | 55.0 µs | (11/2-) | γ→127Cs(100%) | 1980 |
| 128Cs | 73 | 127.9077 | -85,932.0 | --- | 3.64 m | 1+ | β⁺→128Xe(100%) | 1951 |
| 129Cs | 74 | 128.9061 | -87,499.0 | --- | 1.34 d | 1/2+ | β⁺→129Xe(100%) | 1950 |
| 129mCs | 74 | 128.9067 | -86,924.0 | --- | 718.0 ns | (11/2-) | γ→129Cs(100%) | 1977 |
| 130Cs | 75 | 129.9067 | -86,900.0 | --- | 29.21 m | 1+ | β⁺→130Xe(98.4%) β⁻→130Ba(1.6%) | 1952 |
| 130mCs | 75 | 129.9069 | -86,737.0 | --- | 3.46 m | 5- | γ→130Cs(~100%) β⁺→130Xe(0.16%) | 1977 |
| 131Cs | 76 | 130.9055 | -88,055.57 | --- | 9.69 d | 5/2+ | EC→131Xe(100%) | 1947 |
| 132Cs | 77 | 131.9064 | -87,152.7 | --- | 6.48 d | 2+ | β⁺→132Xe(98.13%) β⁻→132Ba(1.87%) | 1953 |
| 134Cs | 79 | 133.9067 | -86,891.165 | --- | 2.07 y | 4+ | β⁻→134Ba(~100%) EC→134Xe(3e-4%) | 1940 |
| 134mCs | 79 | 133.9069 | -86,752.421 | --- | 2.91 h | 8- | γ→134Cs(100%) | 1975 |
| 135Cs | 80 | 134.906 | -87,582.0 | --- | 1.33 My | 7/2+ | β⁻→135Ba(100%) | 1949 |
| 135mCs | 80 | 134.9077 | -85,949.1 | --- | 53.0 m | 19/2- | γ→135Cs(100%) | 1962 |
| 136Cs | 81 | 135.9073 | -86,338.9 | --- | 13.01 d | 5+ | β⁻→136Ba(100%) | 1951 |
| 136mCs | 81 | 135.9079 | -85,821.0 | --- | 17.5 s | 8- | γ→136Cs β⁻→136Ba | 1981 |
| 137Cs | 82 | 136.9071 | -86,545.8 | --- | 30.04 y | 7/2+ | β⁻→137Ba(100%) | 1951 |
| 138Cs | 83 | 137.911 | -82,887.0 | --- | 33.5 m | 3- | β⁻→138Ba(100%) | 1943 |
| 138mCs | 83 | 137.9111 | -82,807.0 | --- | 2.91 m | 6- | γ→138Cs(81%) β⁻→138Ba(19%) | 1971 |
| 139Cs | 84 | 138.9134 | -80,701.0 | --- | 9.27 m | 7/2+ | β⁻→139Ba(100%) | 1939 |
| 140Cs | 85 | 139.9173 | -77,050.0 | --- | 1.06 m | 1- | β⁻→140Ba(100%) | 1950 |
| 140mCs | 85 | 139.9173 | -77,036.0 | --- | 471.0 ns | (2-) | γ→140Cs(100%) | 1974 |
| 141Cs | 86 | 140.92 | -74,477.0 | --- | 24.84 s | 7/2+ | β⁻→141Ba(99.966%) β⁻n→140Ba(0.034%) | 1962 |
| 142Cs | 87 | 141.9243 | -70,515.0 | --- | 1.69 s | 0- | β⁻→142Ba(99.911%) β⁻n→141Ba(0.089%) | 1962 |
| 143Cs | 88 | 142.9273 | -67,676.0 | --- | 1.8 s | 3/2+ | β⁻→143Ba(98.38%) β⁻n→142Ba(1.62%) | 1962 |
| 144Cs | 89 | 143.9321 | -63,271.0 | --- | 994.0 ms | 1- | β⁻→144Ba(97.02%) β⁻n→143Ba(2.98%) | 1967 |
| 144mCs | 89 | 143.9322 | -63,179.0 | --- | 1.1 µs | (4-) | γ→144Cs(100%) | 2009 |
| 144nCs | 89 | 144.0 | 0.0 | --- | --- | (?-) | β⁻→144Ba γ→144Cs β⁻n→143Ba | 1978 |
| 145Cs | 90 | 144.9355 | -60,054.0 | --- | 582.0 ms | 3/2+ | β⁻→145Ba(87.2%) β⁻n→144Ba(12.8%) | 1971 |
| 145mCs | 90 | 144.9363 | -59,291.0 | --- | 500.0 ns | (13/2) | γ→145Cs(100%) | 2015 |
| 146Cs | 91 | 145.9406 | -55,310.4 | --- | 321.6 ms | 1- | β⁻→146Ba(85.8%) β⁻n→145Ba(14.2%) β⁻n→144Ba | 1971 |
| 146mCs | 91 | 145.9407 | -55,263.7 | --- | 1.25 µs | (4-) | γ→146Cs(100%) | 2015 |
| 147Cs | 92 | 146.9443 | -51,920.0 | --- | 230.5 ms | (3/2+) | β⁻→147Ba(71.5%) β⁻n→146Ba(28.5%) | 1978 |
| 147mCs | 92 | 146.945 | -51,219.0 | --- | 190.0 ns | (13/2) | γ→147Cs(100%) | 2015 |
| 148Cs | 93 | 147.9496 | -46,911.0 | --- | 151.8 ms | (2-) | β⁻→148Ba(71.3%) β⁻n→147Ba(28.7%) β⁻n→146Ba | 1978 |
| 148mCs | 93 | 147.9497 | -46,866.0 | --- | 4.8 µs | (4-) | γ→148Cs(100%) | 2015 |
| 149Cs | 94 | 148.9535 | -43,300.0 | --- | 112.3 ms | (3/2+) | β⁻→149Ba(75%) β⁻n→148Ba(25%) β⁻n→147Ba | 1979 |
| 150Cs | 95 | 149.959 | -38,170.0 | --- | 81.0 ms | (2-) | β⁻→150Ba(56%) β⁻n→149Ba(44%) β⁻n→148Ba | 1979 |
| 151Cs | 96 | 150.9632 | -34,280.0 | --- | 59.0 ms | (3/2+) | β⁻→151Ba(100%) β⁻n→150Ba β⁻n→149Ba | 1979 |
| 152Cs | 97 | 151.9687 | -29,130.0 | --- | 17.0 ms | --- | β⁻→152Ba β⁻n→151Ba | 1987 |