Co
Cobalt is a hard, lustrous transition metal known for its blue compounds and use in batteries.
Physical Properties
| Atomic Mass | 58.933 u |
| Density | 8.9 g/cm³ |
| Melting Point | 1768.0 K |
| Boiling Point | 3200.0 K |
| Appearance | Hard, lustrous, bluish-gray metallic |
| State at Room Temp | Solid |
Chemical Properties
| Electronegativity | 1.88 (Pauling) |
| 1st Ionization Energy | 760.4 kJ/mol |
| Electron Affinity | 63.7 kJ/mol |
| Oxidation States | +2, +3, +4, +5 |
Atomic Properties
| Electron Configuration | [Ar] 3d7 4s2 |
| Atomic Radius | 125.0 pm |
| Covalent Radius | 126.0 pm |
| Van der Waals Radius | 192.0 pm |
Discovery
| Discovered By | Georg Brandt |
| Discovery Year | 1735 |
| Location | Stockholm, Sweden |
| Named After | German 'kobald' meaning goblin or evil spirit |
About Cobalt
Cobalt is a hard, lustrous, silver-gray metal with a bluish tinge. Cobalt compounds produce deep blue color in glass and ceramics. It is an essential trace element as a component of vitamin B12.
Uses & Applications
Lithium-ion batteries, superalloys for jet engines, blue pigments, magnetic alloys, and vitamin B12.
Fun Fact
Cobalt gets its name from 'kobold' (German for goblin), because miners blamed goblins for toxic fumes when cobalt ores were smelted.
Isotopes
| Mass Number | Abundance | Half-Life | Stable |
| 59 | 1.0% | - | Yes |
Electron Configuration
[Ar] 3d7 4s2