| Answer | Crossword Clue |
|---|---|
| IONIUM | Radioactive isotope having mass 230 |
| ioniums | naturally occurring radioactive isotope of thorium. Symbol: Io; at. no.: 90; at. wt.: 230 |
| ionium | naturally occurring radioactive isotope of thorium. Symbol: Io; at. no.: 90; at. wt.: 230 |
| radiothorium | a radioactive isotope of thorium with the mass number 228 |
| radiothoriums | RADIOTHORIUM, a radioactive isotope of thorium with the mass number 228 |
| deuterium | isotope of hydrogen, having twice the mass of ordinary hydrogen; heavy hydrogen. Symbol: D; at. wt.: 2.01; at. no.: 1 |
