 |
| General |
| Name | Cobalt |
| Symbol | Co |
| Number | 27 |
| Group Number | 9 |
| Group | Transition metals |
| Block | d |
| Density | 8.90 g/cm3 |
| Atomic Weight | 58.9332 g/mol |
| Atomic Volume | 6.7 cm3/mol |
| Discover | 1737 |
|
| States |
| State | Solid |
| Melting Point | 1768 K |
| Boiling Point | 3200 K |
| Triple Point | Nil |
| Critical Point | Nil |
| Heat of Fusion | 16.06 kJ/mol |
| Heat of Vaporization | 377 kJ/mol |
|
| Energies |
| First Ionization Energy | 758.4 kJ/mole |
| Second Ionization Energy | 1646 kJ/mole |
| Third Ionization Energy | 3232.2 kJ/mole |
| Electronegativity | 1.88 |
| Electron Affinity | 63.8 kJ/mole |
| Specific Heat | 0.42 J/gK |
| Heat Atomization | 425 kJ/mole atoms |
|
| Oxidation and Electrons |
| Shells | 2,8,15,2 |
| Electron Configuration | [Ar] 3d7 4s2 |
| Minimum Oxidation Number | -1 |
| Maximum Oxidation Number | 5 |
| Minimum Common Oxidation Number | 0 |
| Maximum Common Oxidation Number | 3 |
|
| Appearance and Characteristics |
| Crystal Structure | hexagonal |
| Characteristics | hard |
| Color | bluish-white |
| Uses | magnets, Co glass (blue) |
| Hardness | mohs |
| Toxicity | None |
|
| Reactions |
| Reaction with Air | mild, w/ht =>Co3O4 |
| Reaction with 6M HCl | mild, =>H2, CoCl2 |
| Reaction with 15M HNO3 | vigorous, =>Co(NO3)2, NOx |
| Reaction with 6M NaOH | None |
|
| Other Forms |
| Number of Isotopes | 1 |
| Hydride | None |
| Oxide | CoO Co3O4 |
| Chloride | CoCl2 |
|
| Radius |
| Atomic Radius | 125 pm |
| Ionic Radius (1+ ion) | Nil |
| Ionic Radius (1- ion) | Nil |
| Ionic Radius (2+ ion) | 83.8 pm |
| Ionic Radius (2- ion) | Nil |
| Ionic Radius (3+ ion) | 71.8 pm |
|
| Conductivity |
| Thermal Conductivity | 100 J/m-sec-deg |
| Electrical Conductivity | 160.256 1/mohm-cm |
| Polarizability | 7.5 A3 |
|
| Abundance |
| Source | Co sulfides & arsenides |
| Relation Abundance Solar System | 3.352 log |
| Abundance Earth's Crust | 1.4 log |
|
