Co

Cobalt

Identification

CAS Number: 7440-48-4

Discovery Year: 1739

Discoverer: George Brandt

Discovery Location: Sweden

Properties

Atomic Mass: 58.933194 →Density: 8.86 g/cm³ →

Crust Abundance: 25 mg/kg

Crystal Structure: HEX

Atomic Dimensions

Atomic Radius: 135 pm →

Atomic Radius (Rahm): 233 pm

Covalent Radius: 138 pm →

Van der Waals Radius: 200 pm

Metallic Radius: 116 pm

Atomic Volume: 6.7 cm³/mol

Lattice Constant: 2.51 Å

Thermodynamics

Melting Point: 1768 K →Boiling Point: 3143 K →Specific Heat: 0.456 J/(g·K) →Thermal Conductivity: 100 W/(m·K) →Heat of Fusion: 15.48 kJ/mol →Heat of Vaporization: 389.1 kJ/mol →

Heat of Formation: 426.7 kJ/mol

Electronic Structure

Electron Config: [Ar] 3d7 4s2

Block: d

Period: 4 →Group: 9 →Electronegativity: 1.88 →Electron Affinity: 0.66225646 eV →

Oxidation States: +2, +3

Abundance & Geochemistry

Crust Abundance: 25 mg/kg

Sea Abundance: 0.00002 mg/L

Geochemical Class: first series transition metal

Goldschmidt Class: siderophile

About

Light grey transition element. Some meteorites contain small amounts of metallic cobalt. Generally alloyed for use. Mammals require small amounts of cobalt salts. Cobalt-60, an artificially produced radioactive isotope of Cobalt is an important radioactive tracer and cancer-treatment agent. Discovered by G. Brandt in 1737.

Isotopes

Co-59 59 100.00%