Average atomic weight: 127.60(3) u
| Isotope | Fraction | Atomic weight/u |
| 120 | 0.0009(1) | 119.9040593(33) |
| 122 | 0.0255(12) | 121.9030435(16) |
| 123 | 0.0089(3) | 122.9042698(16) |
| 124 | 0.0474(14) | 123.9028171(16) |
| 125 | 0.0707(15) | 124.9044299(16) |
| 126 | 0.1884(25) | 125.9033109(16) |
| 128 | 0.3174(8) | 127.90446128(93) |
| 130 | 0.3408(62) | 129.906222748(12) |
Atomic weights and isotopic compositions were obtained from NIST Database 144
The Atomic Line List does not contain any data for this element
(Atomic Line List v3.00b5)
