The first element produced and identified one atom at a time.
- Atomic number
- 101
- Atomic mass
- [258] u
- Phase
- Solid
- Electron configuration
- [Rn] 5f¹³ 7s²
- Melting point
- 1,100 K · 826.9 °C
- Boiling point
- —
- Density
- 10.3 g/cm³
- Electronegativity
- 1.3
- Period / Group
- 7 / —
- Discovery year
- 1955