| Answer | Crossword Clue |
|---|---|
| ISOTOPE | Carbon 14 or uranium 235 |
| ISOTOPES | Carbon 14 and uranium 235 |
| enriched | Increase the proportion of a particular isotope in (an element), esp. that of the fissile isotope U-235 in uranium so as to make it more powerful or explosive |
| enriching | Increase the proportion of a particular isotope in (an element), esp. that of the fissile isotope U-235 in uranium so as to make it more powerful or explosive |
| ISOTOPE | U-235 or C-14, e.g. |
