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61Pm145
Promethium
LanthanidesBlock fPeriod 6solid at 20 °C
Configuration :[Xe] 4f⁵ 6s²
Atomic mass :145 u
French :Prométhium
3D Bohr-model representation of the Promethium atom (symbol Pm, atomic number Z=61). Electron shell configuration: 2, 8, 18, 23, 8, 2 electrons.
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Bohr model · educational
Electron configuration
Full[Xe] 4f⁵ 6s²
Short[Xe] 4f⁵ 6s²
Valence electrons3
KLMNOPQ shells
K2
L8
M18
N23
O8
P2
Electronegativity
Pauling1.13
Allen—
Mulliken (eV)—
Atomic radii
Empirical185 pm
Calculated205 pm
Covalent199 pm
Van der Waals—
Ionic radii (Shannon-Prewitt)
+397 pm
Successive ionisation energies
I₁540 kJ/mol
I₂1050 kJ/mol
I₃2150 kJ/mol
Electron affinity—
Oxidation states
+2+3
Bold states = most common.