| Answer | Crossword Clue |
|---|---|
| OSMIUM | Densest stable element |
| OSMIUM | Densest natural element |
| HAY | Stable element? |
| fermium | a transuranic element artificially produced by neutron bombardment of plutonium. Symbol: Fm; atomic no: 100; half-life of most stable isotope, 257Fm: 80 days (approx.) |
