Cobalt (Co) — Transition metal. Atomic number 27.
Hard, lustrous gray metal
- Atomic number: 27
- Symbol: Co
- Atomic mass: 58.933 u
- Category: Transition metal
- State: Solid
- Melting point: 1494.85 °C / 1768 K
- Boiling point: 2926.85 °C / 3200 K
- Density: 8.9 g/cm³ (20°C)
- Electron configuration: [Ar] 3d7 4s2
- Oxidation states: +2, +3
- Electronegativity: 1.88
- Discovered by: Georg Brandt (1735)
Common uses: Superalloys, Magnets, Rechargeable batteries
Biological role: Essential in vitamin B12.
Frequently Asked Questions about Cobalt
What is the atomic number of cobalt?
Cobalt has an atomic number of 27, meaning each atom contains 27 protons in its nucleus.
What is the atomic mass of cobalt?
The standard atomic weight of cobalt is 58.933 u (unified atomic mass units).
What category does cobalt belong to?
Cobalt is classified as a transition metal.
What is the state of cobalt at room temperature?
Cobalt is a solid at 20 °C (68 °F).
What is the melting point of cobalt?
The melting point of cobalt is 1494.85 °C / 1768 K.
What is the boiling point of cobalt?
The boiling point of cobalt is 2926.85 °C / 3200 K.
What is the density of cobalt?
The density of cobalt is 8.9 g/cm³ (20°C).
What is the electronegativity of cobalt?
Cobalt has a Pauling electronegativity of 1.88.
What is the electron configuration of cobalt?
The electron configuration of cobalt is [Ar] 3d7 4s2.
What are the common oxidation states of cobalt?
Cobalt commonly exhibits the following oxidation states: +2, +3.
When was cobalt discovered?
Cobalt was discovered in 1735 by Georg Brandt.
Is cobalt radioactive?
Cobalt is a stable element with no naturally occurring radioactive isotopes.
What is the biological role of cobalt?
Essential in vitamin B12.
What are the common uses of cobalt?
Cobalt is used for: Superalloys; Magnets; Rechargeable batteries.
