27
58.93
Co
Cobalt
Identification
CAS Number: 7440-48-4
Discovery Year: 1739
Discoverer: George Brandt
Discovery Location: Sweden
Properties
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
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%
