| Proton | Neutron | Nuclear Spin | Energy State | |
|---|---|---|---|---|
| 112Cs | 55 | 57 | 1 | |
| 113Cs | 55 | 58 | 5/2 | |
| 114Cs | 55 | 59 | 1 | |
| 115Cs | 55 | 60 | 9/2 | |
| 116Cs | 55 | 61 | 1 | |
| 117mCs | 55 | 62 | 3/2 | |
| 117Cs | 55 | 62 | 9/2 | |
| 118mCs | 55 | 63 | -7 | |
| 118Cs | 55 | 63 | 2 | |
| 119mCs | 55 | 64 | 3/2 | |
| 119Cs | 55 | 64 | 9/2 | |
| 120Cs | 55 | 65 | -2 | |
| 120mCs | 55 | 65 | -7 | |
| 121mCs | 55 | 66 | 9/2 | |
| 121Cs | 55 | 66 | 3/2 | |
| 122m3Cs | 55 | 67 | -5 | |
| 122m2Cs | 55 | 67 | -8 | |
| 122Cs | 55 | 67 | 1 | |
| 122m1Cs | 55 | 67 | 3 | |
| 123m1Cs | 55 | 68 | -11/2 | |
| 123Cs | 55 | 68 | 1/2 | |
| 123m2Cs | 55 | 68 | 9/2 | |
| 124Cs | 55 | 69 | 1 | |
| 124mCs | 55 | 69 | 7 | |
| 125Cs | 55 | 70 | 1/2 | |
| 125mCs | 55 | 70 | -11/2 | |
| 126Cs | 55 | 71 | 1 | |
| 127mCs | 55 | 72 | -11/2 | |
| 127Cs | 55 | 72 | 1/2 | |
| 128Cs | 55 | 73 | 1 | |
| 129Cs | 55 | 74 | 1/2 | |
| 130Cs | 55 | 75 | 1 | |
| 130mCs | 55 | 75 | -5 | |
| 131Cs | 55 | 76 | 5/2 | |
| 132Cs | 55 | 77 | 2 | |
| 133Cs | 55 | 78 | 7/2 | Stable |
| 134mCs | 55 | 79 | -8 | |
| 134Cs | 55 | 79 | 4 | |
| 135mCs | 55 | 80 | -19/2 | |
| 135Cs | 55 | 80 | 7/2 | |
| 136Cs | 55 | 81 | 5 | |
| 136mCs | 55 | 81 | -8 | |
| 137Cs | 55 | 82 | 7/2 | |
| 138Cs | 55 | 83 | -3 | |
| 138mCs | 55 | 83 | -6 | |
| 139Cs | 55 | 84 | 7/2 | |
| 140Cs | 55 | 85 | -1 | |
| 141Cs | 55 | 86 | 7/2 | |
| 142Cs | 55 | 87 | 0 | |
| 143Cs | 55 | 88 | 3/2 | |
| 144Cs | 55 | 89 | -1 | |
| 145Cs | 55 | 90 | 3/2 | |
| 146Cs | 55 | 91 | -1 | |
| 147Cs | 55 | 92 | 3/2 | |
| 148Cs | 55 | 93 | 2 | |
| 149Cs | 55 | 94 | 3/2 | |
| 150Cs | 55 | 95 | 2 | |
| 151Cs | 55 | 96 | 3/2 |