| Proton | Neutron | Nuclear Spin | Energy State | |
|---|---|---|---|---|
| 142Er | 68 | 74 | 0 | |
| 143Er | 68 | 75 | -9/2 | |
| 144Er | 68 | 76 | 0 | |
| 145Er | 68 | 77 | 1/2 | |
| 146Er | 68 | 78 | 0 | |
| 147mEr | 68 | 79 | -11/2 | |
| 147Er | 68 | 79 | 1/2 | |
| 148Er | 68 | 80 | 0 | |
| 149m2Er | 68 | 81 | 19/2 | |
| 149Er | 68 | 81 | 1/2 | |
| 149m3Er | 68 | 81 | -27/2 | |
| 149m1Er | 68 | 81 | -11/2 | |
| 150Er | 68 | 82 | 0 | |
| 151m1Er | 68 | 83 | -27/2 | |
| 151Er | 68 | 83 | -7/2 | |
| 152Er | 68 | 84 | 0 | |
| 153Er | 68 | 85 | -7/2 | |
| 154Er | 68 | 86 | 0 | |
| 155Er | 68 | 87 | -7/2 | |
| 156Er | 68 | 88 | 0 | |
| 157mEr | 68 | 89 | 9/2 | |
| 157Er | 68 | 89 | -3/2 | |
| 158Er | 68 | 90 | 0 | |
| 159m1Er | 68 | 91 | 9/2 | |
| 159m2Er | 68 | 91 | -11/2 | |
| 159Er | 68 | 91 | -3/2 | |
| 160Er | 68 | 92 | 0 | |
| 161mEr | 68 | 93 | -11/2 | |
| 161Er | 68 | 93 | -3/2 | |
| 162Er | 68 | 94 | 0 | Stable |
| 163Er | 68 | 95 | -5/2 | |
| 163mEr | 68 | 95 | -11/2 | |
| 164Er | 68 | 96 | 0 | Stable |
| 165Er | 68 | 97 | -5/2 | |
| 166Er | 68 | 98 | 0 | Stable |
| 167Er | 68 | 99 | 7/2 | Stable |
| 167mEr | 68 | 99 | -1/2 | |
| 168Er | 68 | 100 | 0 | Stable |
| 169Er | 68 | 101 | -1/2 | |
| 170Er | 68 | 102 | 0 | Stable |
| 171Er | 68 | 103 | -5/2 | |
| 171mEr | 68 | 103 | -1/2 | |
| 172Er | 68 | 104 | 0 | |
| 173Er | 68 | 105 | -7/2 | |
| 174Er | 68 | 106 | 0 | |
| 175Er | 68 | 107 | 9/2 | |
| 176Er | 68 | 108 | 0 | |
| 177Er | 68 | 109 | -1/2 |