Average atomic weight: 78.971(8) u
| Isotope | Fraction | Atomic weight/u |
| 74 | 0.0089(4) | 73.922475934(15) |
| 76 | 0.0937(29) | 75.919213704(17) |
| 77 | 0.0763(16) | 76.919914154(67) |
| 78 | 0.2377(28) | 77.91730928(20) |
| 80 | 0.4961(41) | 79.9165218(13) |
| 82 | 0.0873(22) | 81.9166995(15) |
Atomic weights and isotopic compositions were obtained from NIST Database 144
Se I (Se-like): 168 levels, 3778 lines (E1: 1805 IC: 1963 M1: 5 E2: 4 M2: 1), transition probabilities for 2 lines
Se II (As-like): 41 levels, 332 lines (E1: 146 IC: 176 M1: 6 E2: 4), transition probabilities for 2 lines
Se III (Ge-like): 51 levels, 342 lines (E1: 192 IC: 144 M1: 4 E2: 2), transition probabilities for 2 lines
Se IV (Ga-like): 28 levels, 124 lines (E1: 93 IC: 26 M1: 3 E2: 1 M2: 1), transition probabilities for 3 lines
Se V (Zn-like): 14 levels, 33 lines (E1: 18 IC: 11 M1: 2 E2: 1 M2: 1), transition probabilities for 2 lines
Se VI (Cu-like): 6 levels, 7 lines (E1: 7), transition probabilities for 0 lines
Se VII (Ni-like): 44 levels, 146 lines (E1: 83 IC: 55 M1: 5 E2: 3), transition probabilities for 2 lines
Se VIII (Co-like): 36 levels, 56 lines (E1: 33 IC: 22 M1: 1), transition probabilities for 1 lines
Se IX (Fe-like): 1 levels, 0 lines
Se X (Mn-like): 1 levels, 0 lines
Se XI (Cr-like): 1 levels, 0 lines
Se XII (V -like): 1 levels, 0 lines
Se XIII (Ti-like): 1 levels, 0 lines
Se XIV (Sc-like): 1 levels, 0 lines
Se XV (Ca-like): 3 levels, 1 lines (E1: 1), transition probabilities for 0 lines
Se XVI (K -like): 6 levels, 4 lines (E1: 4), transition probabilities for 0 lines
Se XVII (Ar-like): 2 levels, 1 lines (E1: 1), transition probabilities for 0 lines
Se XVIII (Cl-like): 8 levels, 7 lines (E1: 6 M1: 1), transition probabilities for 1 lines
Se XIX (S -like): 9 levels, 14 lines (E1: 3 IC: 2 M1: 5 E2: 4), transition probabilities for 2 lines
Se XX (P -like): 7 levels, 15 lines (E1: 2 IC: 3 M1: 6 E2: 4), transition probabilities for 2 lines
Se XXI (Si-like): 6 levels, 11 lines (E1: 1 IC: 1 M1: 5 E2: 4), transition probabilities for 2 lines
Se XXII (Al-like): 5 levels, 3 lines (E1: 3), transition probabilities for 0 lines
Se XXIII (Mg-like): 17 levels, 30 lines (E1: 17 IC: 11 M1: 1 M2: 1), transition probabilities for 1 lines
Se XXIV (Na-like): 19 levels, 29 lines (E1: 29), transition probabilities for 29 lines
Se XXV (Ne-like): 19 levels, 18 lines (E1: 16 IC: 2), transition probabilities for 0 lines
Se XXVI (F -like): 51 levels, 83 lines (E1: 59 IC: 23 M1: 1), transition probabilities for 1 lines
Se XXVII (O -like): 54 levels, 171 lines (E1: 82 IC: 80 M1: 5 E2: 4), transition probabilities for 2 lines
Se XXVIII (N -like): 1 levels, 0 lines
Se XXIX (C -like): 1 levels, 0 lines
Se XXX (B -like): 2 levels, 1 lines (M1: 1), transition probabilities for 1 lines
Se XXXI (Be-like): 24 levels, 109 lines (E1: 58 IC: 47 M1: 2 E2: 1 M2: 1), transition probabilities for 2 lines
Se XXXII (Li-like): 3 levels, 2 lines (E1: 2), transition probabilities for 2 lines
Se XXXIII (He-like): 28 levels, 131 lines (E1: 88 IC: 43), transition probabilities for 84 lines
Se XXXIV (H -like): 100 levels, 919 lines (E1: 919), transition probabilities for 919 lines
(Atomic Line List v3.00b5)
