Ru

Ruthenium

Identification

CAS Number: 7440-18-8

Discovery Year: 1844

Discoverer: Karl Klaus

Discovery Location: Russia

Properties

Atomic Mass: 101.07 →Density: 12.1 g/cm³ →

Crust Abundance: 0.001 mg/kg

Crystal Structure: HEX

Atomic Dimensions

Atomic Radius: 130 pm →

Atomic Radius (Rahm): 237 pm

Covalent Radius: 146 pm →

Van der Waals Radius: 213 pm

Metallic Radius: 125 pm

Atomic Volume: 8.3 cm³/mol

Lattice Constant: 2.7 Å

Thermodynamics

Melting Point: 2583 K →Boiling Point: 4173 K →Specific Heat: 0.238 J/(g·K) →Thermal Conductivity: 117 W/(m·K) →Heat of Fusion: 25.5 kJ/mol →

Heat of Formation: 650.6 kJ/mol

Electronic Structure

Electron Config: [Kr] 4d7 5s

Block: d

Period: 5 →Group: 8 →Electronegativity: 2.2 →Electron Affinity: 1.05 eV →

Oxidation States: +2, +3, +4, +6, +8

Abundance & Geochemistry

Crust Abundance: 0.001 mg/kg

Sea Abundance: 7e-7 mg/L

Geochemical Class: noble metal

Goldschmidt Class: siderophile

About

Hard white metallic transition element. Found with platinum, used as a catalyst in some platinum alloys. Dissolves in fused alkalis, and is not attacked by acids. Reacts with halogens and oxygen at high temperatures. Isolated in 1844 by K.K. Klaus.

Isotopes

Ru-102 102 31.55%

Ru-104 104 18.62%

Ru-101 101 17.06%

Ru-99 99 12.76%

Ru-100 100 12.60%

Ru-96 96 5.54%

Ru-98 98 1.87%