Cobalt

Symbol: Co
Atomic number: 27
Category: transition metals
Group: 9
Period: 4
Block: d
Atomic weight: 58.9332 g/mol
Electrons per shell: 2, 8, 15, 2
CAS number: 7440-48-4
Phase: solid
Density: 8.90 kg/dm³ (near room temperature)
Melting point: 1768 K (1495 °C, 2723 °F)
Boiling point: 3200 K (2927 °C, 5301 °F)
Crystal structure: hexagonal
Oxidation states: 4, 3, 2, 1
Electronegativity: 1.88 (Pauling scale)
Name's origin: kobold
Name's meaning: goblin: a term used for the ore of cobalt by miners
Facts:
- is a hard, lustrous, grey metal
- is found in various metallic-lustred ores for example cobaltite, but it is produced as a by- product of copper and nickel mining
- is at higher levels of exposure mutagenic and carcinogenic
- is an essential trace-element for all multicellular organisms as the active center of coenzymes called cobalamins
- is mostly used in superalloys for e.g. jet engines, and is also used in batteries (lithium cobalt oxide is used in Li-ion batteries), catalysts, pigments and electroplating