To share this content with an AI assistant
57La138.905
Lanthanum
LanthanidesBlock fPeriod 6solid at 20 °C
Configuration :[Xe] 5d¹ 6s²
Atomic mass :138.90547 u
French :Lanthane
3D Bohr-model representation of the Lanthanum atom (symbol La, atomic number Z=57). Electron shell configuration: 2, 8, 18, 18, 9, 2 electrons.
Scroll to activate 3D
Bohr model · educational
Electron configuration
Full[Xe] 5d¹ 6s²
Short[Xe] 5d¹ 6s²
Valence electrons3
KLMNOPQ shells
K2
L8
M18
N18
O9
P2
Electronegativity
Pauling1.1
Allen—
Mulliken (eV)—
Atomic radii
Empirical195 pm
Calculated226 pm
Covalent207 pm
Van der Waals—
Ionic radii (Shannon-Prewitt)
+3103.2 pm
Successive ionisation energies
I₁538.1 kJ/mol
I₂1067 kJ/mol
I₃1850.3 kJ/mol
Electron affinity—
Oxidation states
+2+3
Bold states = most common.