Electronic data		Thermal data		Steric data
Shells: 2,8,15,2 Orbitals: [Ar] 3d7 4s2 Electronegativity: 1.7, 1.9 1. Ionization potential: 7.8810 eV 2. Ionization potential: 17.06 eV 3. Ionization potential: 33.50 eV Oxidation states: 3,2,0,-1 Electrical conductivity: 0.172 10^6		Melting point: 1495 °C Boiling point: 2927 °C Specific heat: 0.42 J/gK Heat of fusion: 16.190 kJ/mol Heat of vaporization: 376.50 kJ/mol Thermal conductivity: 1.00 W/cmK		Atomic radius: 1.67 Å Ionic radius: 0.65 Å () Covalent radius: 1.16 Å Atomic volume: 6.7 cm³/mol Density (293 K): 8.90 g/cm³ Crystal structure: Hexagonal

Nuclide	Abundance [%]	Mass	Spin	Halflife	Decay mode	Decay tree
56Co	0	55.94	4	77.3d	EC,+	View
57Co	0	56.936	7/2	271.8d	EC	View
58Co	0	57.936	2	70.88d	EC,+	View
58Com	0	58	5	9.1h	IT	View
59Co	100	58.9332	7/2	--	stable	--
60Co	0	59.934	5	5.271y	-	View
60Com	0	60	2	10.47m	IT,-	View
61Co	0	61	7/2	1.65h	-	View

Legend

Name origin:	German: Kobold (goblin)
Description:	Hard, ductile, lustrous bluish-gray metal. Exists in the earth's crust in concentrations of about 25 ppm. It has remarkable magnetic properties.
Discovered by:	George Brandt
Year:	1739
Place:	Sweden
Sources:	Occurs in compounds with arsenic, oxygen and sulfur as in cobaltine (CoAsS) and linneite (Co3S4). Pure cobalt is obtained as a byproduct of refining nickel, copper and iron.
Use(s):	Used in many hard alloys; for magnets, ceramics and special glasses. Remains hard up to 982°C. Radioactive cobalt-60 is used in cancer therapy.