Discovered in the fallout of the first hydrogen bomb test, in samples flown through the cloud.
- Atomic number
- 99
- Atomic mass
- [252] u
- Phase
- Solid
- Electron configuration
- [Rn] 5f¹¹ 7s²
- Melting point
- 1,133 K · 859.9 °C
- Boiling point
- 1,269 K · 995.9 °C
- Density
- 8.84 g/cm³
- Electronegativity
- 1.3
- Period / Group
- 7 / —
- Discovery year
- 1952