57
La
Lanthanum
Lanthanide period 6 f-block discovered: 1839
As a chemical element
Properties of the atom — they do not depend on what substance it is part of.
- Atomic number
- 57
- Atomic mass
- 138.9055 a.m.u.
- Electron configuration
- [Xe]6s2 5d1
- Electronegativity
- 1.1 on the Pauling scale
- Atomic radius
- 240 pm
- Ionization energy
- 5.577 eV
- Electron affinity
- 0.5 eV
- Oxidation states
- +3
As a simple substance
Properties of the substance these atoms form under ordinary conditions.
- State at 25 °C
- Solid
- Melting point
- 1191 K (917,85 °C)
- Boiling point
- 3737 K (3 463,85 °C)
- Density
- 6.15 g/cm³