| Isotope | Relative Atomic Mass |
Isotopic Composition |
Standard Atomic Weight |
Notes | ||||
|---|---|---|---|---|---|---|---|---|
 | ||||||||
| 68 | Er | 162 | 161.928 7884(20) | 0.001 39(5) | 167.259(3) | g | ||
| 164 | 163.929 2088(20) | 0.016 01(3) | ||||||
| 166 | 165.930 2995(22) | 0.335 03(36) | ||||||
| 167 | 166.932 0546(22) | 0.228 69(9) | ||||||
| 168 | 167.932 3767(22) | 0.269 78(18) | ||||||
| 170 | 169.935 4702(26) | 0.149 10(36) | ||||||
| ||||||||
