Eu

Europium

Identification

CAS Number: 7440-53-1

Discovery Year: 1901

Discoverer: Eugène Demarçay

Discovery Location: France

Properties

Atomic Mass: 151.964 →Density: 5.24 g/cm³ →

Crust Abundance: 2 mg/kg

Crystal Structure: BCC

Atomic Dimensions

Atomic Radius: 185 pm →

Atomic Radius (Rahm): 280 pm

Covalent Radius: 198 pm →

Van der Waals Radius: 235 pm

Atomic Volume: 28.9 cm³/mol

Lattice Constant: 4.61 Å

Thermodynamics

Melting Point: 1095 K →Boiling Point: 1870 K →Specific Heat: 0.176 J/(g·K) →Thermal Conductivity: 13.9 W/(m·K) →Heat of Vaporization: 176 kJ/mol →

Heat of Formation: 177.4 kJ/mol

Electronic Structure

Electron Config: [Xe] 4f7 6s2

Block: f

Period: 6 →Electron Affinity: 0.8640000000000001 eV →

Oxidation States: +2, +3

Abundance & Geochemistry

Crust Abundance: 2 mg/kg

Sea Abundance: 1.3e-7 mg/L

Geochemical Class: rare earth & related

Goldschmidt Class: litophile

About

Soft silvery metallic element belonging to the lanthanoids. Eu-151 and Eu-153 are the only two stable isotopes, both of which are Neutron absorbers. Discovered in 1889 by Sir William Crookes.

Isotopes

Eu-153 153 52.19%

Eu-151 151 47.81%