Tableau périodique

Lanthane (La)

Lanthane is the chemical element with atomic number 57 and symbol La. It is a lanthanide in period 6, with a standard atomic weight of 138.91 u.

Faits essentiels

Z
57
Atomic weight
138.91 u
Category
lanthanide
State at 298 K
Solid
Occurrence
primordial
Discovered
1839
CAS
7439-91-0

Propriétés mesurées

PropertyValueSource
Electronegativity 1.1 National Center for Biotechnology Information (NIH)
Melting point 1,191 K National Center for Biotechnology Information (NIH)
Boiling point 3,737 K National Center for Biotechnology Information (NIH)
Density stp 6.15 g/cm³ National Center for Biotechnology Information (NIH)
Atomic radius empirical 240 pm National Center for Biotechnology Information (NIH)
Ionization energy 1st 538.1 kJ/mol National Center for Biotechnology Information (NIH)
Electron affinity 48.2 kJ/mol National Center for Biotechnology Information (NIH)

Configuration électronique

2 8 18 18 9 2 La
Noble gas notation
[Xe] 5d¹ 6s²
Full notation
1s² 2s² 2p⁶ 3s² 3p⁶ 3d¹⁰ 4s² 4p⁶ 4d¹⁰ 5s² 5p⁶ 5d¹ 6s²
Electrons per shell
2, 8, 18, 18, 9, 2

Isotopes

Sources