| Answer | Crossword Clue |
|---|---|
| RADON | Product of radium disintegration |
| em | gaseous product of radioactive disintegration, including radon, thoron, and actinon. Symbol: Em |
| francium | a short-lived radioactive element of the alkali-metal group occurring naturally as a disintegration product of actinium and also produced artificially see element table |
| franciums | a short-lived radioactive element of the alkali-metal group occurring naturally as a disintegration product of actinium and also produced artificially see element table |
