in choosing which isotopes to search.
| Isotope | Relative Atomic Mass |
Isotopic Composition |
Standard Atomic Weight |
Notes | ||||
|---|---|---|---|---|---|---|---|---|
 | ||||||||
| 9 | F | 19 | 18.998 403 22(7) | 1.0000 | 18.998 403 2(5) | |||
| 19 | K | 39 | 38.963 706 68(20) | 0.932 581(44) | 39.0983(1) | g | ||
| 40 | 39.963 998 48(21) | 0.000 117(1) | ||||||
| 41 | 40.961 825 76(21) | 0.067 302(44) | ||||||
| ||||||||
