Danh sách đồng vị
Chu kỳ 6 > Caesi, Z=55

| Đồng vị | Kỳ bán rã | Năng lượng  phân rã, MeV | Spin /  Chẵn lẻ | Phân rã, % | Tỷ lệ, % |
| --- | --- | --- | --- | --- | --- |
| 113Cs | 17 µs | 0,974 | (5/2+) | p ≈ 100, K/β+ ≈ 0,03 |   |
| 114Cs | 0,57 s | 9,3 (K/β+), 3,36 (α), 9,3 (Kp), 15,3 (Kα) | (1+) | K/β+ ≈ 100, α = 0,018, Kp = 7, Kα = 0,16 |   |
| 115Cs | 1,4 s | 8,8 (K/β+), 5,8 (Kp) |  | K/β+ = 100, Kp ≈ 0,07 |   |
| 116Cs | 3,84 s | 10,5 | >4+ | K/β+ = 100, Kp = 0,44, Kα = 0,08 |   |
| 116m1Cs | 0,70 s | 10,5 (K/β+), 6,7 (Kp), 12,4 (Kα) | (1+) | K/β+ = 100, Kp = 0,28, Kα = 0,049 |   |
| 117Cs | 8,4 s | 7,52 | (9/2+) | K/β+ = 100 |   |
| 117m1Cs | 6,5 s | 7,67 | (3/2+) | K/β+ = 100 |   |
| 118Cs | 14 s | 9,3 (K/β+), 4,73 (Kp), 11,08 (Kα) | 2 | K/β+ = 100, Kp < 4,2 × 10−2, Kα < 2,4 × 10−3 |   |
| 118m1Cs | 17 s | 9,3 (K/β+), 4,73 (Kp), 11,08 (Kα) | (7−) | K/β+ = 100, Kp < 4,2 × 10−2, Kα < 2,4 × 10−3 |   |
| 119Cs | 43,0 s | 6,33 | 9/2+ | K/β+ = 100 |   |
| 119m1Cs | 30,4 s | 6,33 | 3/2(+) | K/β+ = 100 |   |
| 120Cs | 64 s | 7,92 (K/β+) | 2 | K/β+ = 100 |   |
| 120m1Cs | 57 s | 7,92 (K/β+), 2,47 (Kp) |  | K/β+ = 100, Kp = 7 × 10−6, Kα = 2,0 × 10−5 |   |
| 121Cs | 155 s | 5,40 | 3/2(+) | K/β+ = 100 |   |
| 121m1Cs | 122 s | 5,468 (K/β+), 0,068 (IT) | 9/2(+) | K/β+ = 83, IT = 17 |   |
| 122Cs | 21,0 s | 7,050 | 1+ | K/β+ = 100 |   |
| 122m1Cs | 3,70 min | 7,126 | 8− | K/β+ = 100 |   |
| 122m2Cs | 0,36 s | 0,127 | (5) − | IT = 100 |   |
| 123Cs | 5,94 min | 4,200 | 1/2+ | K/β+ = 100 |   |
| 123m1Cs | 1,64 s | 0,157 | (11/2) − | IT = 100 |   |
| 124Cs | 30,8 s | 5,951 | 1+ | K/β+ = 100 |   |
| 124m1Cs | 6,3 s | 0,463 | (7) + | IT = 100 |   |
| 125Cs | 45 min | 3,092 | (1/2+) | K/β+ = 100 |   |
| 126Cs | 1,64 min | 4,826 | 1+ | K/β+ = 100 |   |
| 127Cs | 6,25 h | 2,085 | 1/2+ | K/β+ = 100 |   |
| 128Cs | 3,66 min | 3,930 | 1+ | K/β+ = 100 |   |
| 129Cs | 32,06 h | 1,196 | 1/2+ | K/β+ = 100 |   |
| 130Cs | 29,21 min | 2,983 (K/β+), 0,373 (β−) | 1+ | K/β+ = 98,4, β− = 1,6 |   |
| 130m1Cs | 3,46 min | 0,163 (IT), 3,146 (K/β+) | 5− | IT = 99,84, K/β+ = 0,16 |   |
| 131Cs | 9,689 d | 0,352 | 5/2+ | K = 100 |   |
| 132Cs | 6,479 d | 2,120 | 2+ | K/β+ = 98,13, β− = 1,87 |   |
| 133Cs | Bền |  | 7/2+ |   | 100 |
| 134Cs | 2,0648 a | 2,059 (β−), 1,229 (K) | 4+ | β− = 99,9997, K = 0,0003 |   |
| 134m1Cs | 2,903 h | 0,139 | 8− | IT = 100 |   |
| 135Cs | 2,3 × 106 a | 0,269 | 7/2+ | β− = 100 |   |
| 135m1Cs | 53 min | 1,633 | 19/2− | IT = 100 |   |
| 136Cs | 13,16 d | 2,548 | 5+ | β− = 100 |   |
| 136m1Cs | 19 s |  ? (IT), 2,548 (β−) | 8− | IT = ?, β− = ? |   |
| 137Cs | 30,17 a | 1,176 | 7/2+ | β− = 100 |   |
| 138Cs | 33,41 min | 5,373 | 3− | β− = 100 |   |
| 138m1Cs | 2,91 min | 5,453 (β−), 0,080 (IT) | 6− | β− = 19, IT = 81 |   |
| 139Cs | 9,27 min | 4,213 | 7/2+ | β− = 100 |   |
| 140Cs | 63,7 s | 6,219 | 1− | β− = 100 |   |
| 141Cs | 24,94 s | 5,255 (β−), 0,735 (β−n) | 7/2+ | β− = 100, β−n = 0,029 |   |
| 142Cs | 1,70 s | 7,306 (β−), 1,337 (β−n) | 0− | β− = 100, β−n = 0,091 |   |
| 143Cs | 1,78 s | 6,243 (β−), 2,048 (β−n) | 3/2+ | β− = 100, β−n = 1,62 |   |
| 144Cs | 1,01 s | 8,465 (β−), 2,56 (β−n) | 1 | β− = 100, β−n = 3,17 |   |
| 144m1Cs | 1 s | 8,465 | (GE 4) | β− = ? |   |
| 145Cs | 0,594 s | 7,89 (β−), 3,55 (β−n) | 3/2+ | β− = 100, β−n = 13,8 |   |
| 146Cs | 0,321 s | 9,38 (β−), 4,32 (β−n) | 1− | β− = 100, β−n = 14,2 |   |
| 147Cs | 0,225 s | 9,25 (β−), 4,74 (β−n) | (3/2+) | β− = 100, β−n = 43 |   |
| 148Cs | 158 ms | 10,5 (β−) |  | β− = 100, β−n = 25 |   |