Cobalt
Definition and meaning of Cobalt in chemistry.
Cobalt is a chemical element with the symbol Co and atomic number 27. It is a hard, lustrous, silver-gray transition metal that is found primarily in chemically combined forms within the Earth's crust.
In more detail
Located in group 9 of the periodic table, cobalt is a ferromagnetic metal that retains its magnetic properties at extremely high temperatures, possessing a high Curie temperature of 1121 degrees Celsius. It rarely occurs as a native metal but is typically extracted as a byproduct of copper and nickel mining. The element exhibits a versatile coordination chemistry, predominantly forming stable compounds in the +2 and +3 oxidation states, many of which display intense blue or pink colors depending on their hydration state and ligands. Cobalt is uniquely resistant to oxidation and maintains its strength under extreme stress and heat, making it an ideal component for high-performance superalloys used in jet turbines. Biologically, cobalt is an essential trace element for all animals, as it forms the active center of coenzymes called cobalamins, the most well-known being vitamin B12. Radioactive isotopes of cobalt, particularly cobalt-60, are also utilized extensively in medical radiotherapy.
Key facts
| Field | General Chemistry |
|---|---|
| Symbol | Co |
| Atomic number | 27 |
| Atomic mass | 58.933 u |
| Category | Transition Metal |
| State at room temperature | Solid |
| Melting point | 1495 °C |
| Boiling point | 2927 °C |
| Year discovered | 1735 |
Cobalt is a crucial component in the manufacturing of lithium-ion batteries, where it is used in the cathode to increase the energy density and stabilize the battery structure.
Frequently asked questions
Why is cobalt used in permanent magnets?
Cobalt is used to make strong permanent magnets, such as alnico and samarium-cobalt magnets, because it enhances magnetic strength and provides excellent temperature stability.
What is the biological significance of cobalt?
Cobalt is biologically significant because it is a key structural component of vitamin B12, which is essential for red blood cell formation and neurological function in animals.