57
La
138.91
Lanthanum
Element 57 · 138.91 u · f-block
lanthanide
The first of the lanthanide series. Used in camera lenses, battery electrodes, and lighter flints.
Phase (STP)
Solid
Melting Point
920 °C
Boiling Point
3464 °C
Density
6.145 g/cm³
Electronegativity
1.1
Atomic Radius
195 pm
Ionization Energy
538 kJ/mol
Electron Affinity
50 kJ/mol
Discovered
1839 · Carl Gustaf Mosander
Electron Configuration
[Xe] 5d1 6s2
Electron Orbitals
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