57 · La
Lanthanum
Separated by Mosander in 1839.
Identity
- Atomic number
- 57
- Symbol
- La
- Canonical name
- Lanthanum
- Category
- lanthanide
- Group
- unassigned
- Period
- 6
- Block
- f
Series set apart from the main table. Whether group 3 is lanthanum or lutetium (actinium or lawrencium) is still discussed, so the group is left empty.
Properties
These quantities come from the Periodic Table JSON compilation. They have not yet been checked, one by one, against CIAAW atomic weights or NIST measurements. A value marked estimated is not a measurement.
- Atomic mass
- 138.905477 u
- Electron configuration
- [Xe] 5d16s2
- Electrons per shell
- 2, 8, 18, 18, 9, 2
- Standard state
- solid
- Density
- 6.162 g/cm³
- Melting point
- 1,193 K
- Boiling point
- 3,737 K
- Electronegativity
- 1.1 Pauling
- First ionization energy
- 538.1 kJ/mol
- Electron affinity
- 53 kJ/mol
History
Lanthanum hidden in ceria
Discovery · confirmed · 1839
Mosander separates lanthanum from a cerium nitrate.
Etymology
- Theme
- property
- Language
- grec
- Root
- lanthanein
- Meaning
- that which lies hidden
Scientists
Places and institutions
- Stockholm — historical setting : Sweden — present country : Sweden
See also
Sources
- IUPAC, Periodic Table of the Elements
- Bowserinator, Periodic Table JSON. Compilation secondaire d’où viennent les grandeurs physiques importées (masse, densité, températures, énergies). Elles ne sont pas revérifiées une à une auprès du NIST ou de la CIAAW.
- John Emsley, Nature’s Building Blocks: An A–Z Guide to the Elements