About

Europium is a moderately hard, silvery rare-earth metal, the most reactive of its series. It is brilliantly fluorescent under UV light, making it crucial as the red and blue phosphors in television screens and fluorescent lamps, providing color fidelity. It is also used in anti-counterfeiting phosphors embedded in Euro banknotes to ensure their authenticity.

Atomic Properties

Atomic Number63

Atomic Weight151.964 u

Neutrons (common)90

Electron Configuration[Xe] 4f⁷ 6s²

Full Configuration1s² 2s² 2p⁶ 3s² 3p⁶ 3d¹⁰ 4s² 4p⁶ 4d¹⁰ 4f⁷ 5s² 5p⁶ 6s²

Electrons per Shell2, 8, 18, 25, 8, 2

Electronegativity1.2

Electron Affinity50.1 kJ/mol

Oxidation States+3, +2

Covalent Radius185 pm

Ionic Radius94.7 pm

Periodic Table Position

Group3

Period6

BlockF

Chemical SeriesLanthanoids

Physical Properties

State at STPsolid

AppearanceSilvery-white metallic

Density at STP5.244 g/cm³

Crystal Structurebcc

Magnetic Orderingparamagnetic

Poisson Ratio0.152

Thermal Properties

Melting Point1,099 K

Boiling Point1,802 K

Thermal Expansion0 1/K

Thermal Conductivity13.9 W/(m·K)

Specific Heat0.182 J/(g·K)

Molar Heat27.66 J/(mol·K)

Heat of Fusion9.21 kJ/mol

Heat of Vaporization176 kJ/mol

Abundance

In Earth's Crust2 ppm

In Ocean0 ppm

In Solar System0.071 ppm

In Universe0.001 ppm

Discovery

Discovered byEugène-Anatole Demarçay

Discovery Year1,901

Occurrenceprimordial

CAS Number7440-53-1

Electron Configuration

Energy

↿⇂

↿

Isotopes of Europium

Symbol ▲	Mass (u) ▲	Abundance ▲	Half-life ▲	Decay Mode ▲
¹⁵¹Eu	150.919850	47.81%	4.6 Ey	Alpha Decay
¹⁵³Eu	152.921230	52.19%	Stable	Stable

Interactive Visualization

Explore the 3D Bohr model of Europium in our interactive viewer.

View 3D Model of Europium