63Eu151.964

Europium

LanthanidesBlock fPeriod 6solid at 20 °C
Configuration :
[Xe] 4f⁷ 6s²
Atomic mass :
151.964 u
3D Bohr-model representation of the Europium atom (symbol Eu, atomic number Z=63). Electron shell configuration: 2, 8, 18, 25, 8, 2 electrons.
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Bohr model · educational

Bohr model of europium

Bohr model of europium (Eu): 63 electrons in 6 shells — 2, 8, 18, 25, 8, 2

Europium (Eu) has 63 electrons, spread over 6 shells. The diagram places them on circles around the nucleus, from the K shell — the closest — outward.

ShellElectrons
K (n = 1)2
L (n = 2)8
M (n = 3)18
N (n = 4)25
O (n = 5)8
P (n = 6)2

The Bohr model is a teaching picture: electrons do not travel in circular orbits, but the number of electrons per shell is exact.

Electron configuration

Full1s² 2s² 2p⁶ 3s² 3p⁶ 3d¹⁰ 4s² 4p⁶ 4d¹⁰ 5s² 5p⁶ 4f⁷ 6s²
Short[Xe] 4f⁷ 6s²
Valence electrons3
KLMNOPQ shells
K2
L8
M18
N25
O8
P2

Electronegativity

Pauling1.2
Allen—
Mulliken (eV)—

Atomic radii

Empirical185 pm
Calculated231 pm
Covalent198 pm
Van der Waals—
Ionic radii (Shannon-Prewitt)
+2117 pm
+394.7 pm

Successive ionisation energies

I₁547.1 kJ/mol
I₂1085 kJ/mol
I₃2404 kJ/mol
I₄4120 kJ/mol
Electron affinity—

Oxidation states

+2+3
Bold states = most common.
Warm-up

Europium — do you remember?

3 questions on this page. The right answer shows every time, and nothing is asked of you to play.

No account · one minute

Period 6Block fFamily Lanthanides
Sources : NIST Atomic Weights & Isotopic Compositions, IUPAC Recommendations, CODATA. Methodology