103 Lr
Actinide
Lawrencium
Last actinide.
Properties of Lawrencium
- Atomic number (Z)
- 103
- Symbol
- Lr
- Atomic mass
- 266 g/mol
- Category
- Actinide
- Group
- 3
- Period
- 7
- Electron configuration
- [Rn] 5f¹⁴ 7s² 7p¹
- Electronegativity (Pauling)
- 1.3
- Atomic radius
- —
- First ionization energy
- 470 kJ/mol
- Melting point
- 1900 K (1626.8 °C)
- Boiling point
- —
- Density
- —
- Phase at 25 °C
- Solid
- Discovered
- Discovered in 1961