| Answer | Crossword Clue |
|---|---|
| thorons | THORON, a radioactive isotope of radon |
| thoron | a radioactive isotope of radon |
| em | gaseous product of radioactive disintegration, including radon, thoron, and actinon. Symbol: Em |
| thoron | radioactive isotope of radon, produced by the disintegration of thorium. Symbol: Tn; at. wt.: 220; at. no.: 86 |
| thorons | radioactive isotope of radon, produced by the disintegration of thorium. Symbol: Tn; at. wt.: 220; at. no.: 86 |
| actinons | chemically inert, gaseous, short-lived isotope of radon that is a member of the actinium series. Symbol: An; at. no.: 86; at. wt.: 219 |
| actinon | chemically inert, gaseous, short-lived isotope of radon that is a member of the actinium series. Symbol: An; at. no.: 86; at. wt.: 219 |
