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27Co58.933
Cobalt
Transition MetalCobalt is a chemical element with symbol Co and atomic number 27. Like nickel, cobalt in the Earth's crust is found only in chemically combined form, save for small deposits found in alloys of natural meteoric iron. The free element, produced by reductive smelting, is a hard, lustrous, silver-gray metal.
Phase: SolidAppearance: hard lustrous gray metal
2, 8, 15, 2
Physical Properties
Atomic Mass58.9331944 u
Density8.9 g/cm³
Melting Point1768 K
Boiling Point3200 K
Molar Heat24.81 J/(mol·K)
Period4
PhaseSolid
Chemical Properties
Electron Configuration1s2 2s2 2p6 3s2 3p6 4s2 3d7
Semantic Config[Ar] 3d7 4s2
Shells2, 8, 15, 2
Electron Affinity63.898 kJ/mol
Electronegativity1.88
Ionization Energies
IE1: 760.4 kJ/molIE2: 1648 kJ/molIE3: 3232 kJ/molIE4: 4950 kJ/molIE5: 7670 kJ/molIE6: 9840 kJ/molIE7: 12440 kJ/molIE8: 15230 kJ/molIE9: 17959 kJ/molIE10: 26570 kJ/molIE11: 29400 kJ/molIE12: 32400 kJ/molIE13: 36600 kJ/molIE14: 39700 kJ/molIE15: 42800 kJ/molIE16: 49396 kJ/molIE17: 52737 kJ/molIE18: 134810 kJ/molIE19: 145170 kJ/molIE20: 154700 kJ/molIE21: 167400 kJ/molIE22: 178100 kJ/molIE23: 189300 kJ/molIE24: 204500 kJ/molIE25: 214100 kJ/molIE26: 920870 kJ/molIE27: 966023 kJ/mol
Discovery