27 Co 58.933
Cobalt
transition metal
Properties
- Atomic number
- 27
- Atomic mass
- 58.933 u
- Category
- transition metal
- Group
- 9
- Period
- 4
- Block
- d-block
- State (room temp)
- Solid
- Outer-shell electrons
- 2
- Electronegativity
- 1.88 (Pauling)
- Density
- 8.9 g/cm³
- Melting point
- 1494.85 °C
- Boiling point
- 2926.85 °C
Electron configuration
1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d⁷
Noble-gas shorthand: [Ar] 3d⁷ 4s²
Electrons per shell: 2, 8, 15, 2, which is 2 in the outermost shell.
Related: electron configuration, the Bohr model, valence electrons.
About Cobalt
Cobalt is a chemical element with symbol Co and atomic number 27. Like nickel, cobalt in the Earth's crust is found only in chemically combined form, save for small deposits found in alloys of natural meteoric iron. The free element, produced by reductive smelting, is a hard, lustrous, silver-gray metal.
- Discovered by Georg Brandt
- Appearance: hard lustrous gray metal
Cobalt: frequently asked questions
- What is Cobalt?
- Cobalt (Co) is the chemical element with atomic number 27. It is a metal: specifically a transition metal.
- What is the atomic number of Cobalt?
- Cobalt's atomic number is 27, which means every Cobalt atom has 27 protons in its nucleus.
- What is the electron configuration of Cobalt?
- The electron configuration of Cobalt is 1s2 2s2 2p6 3s2 3p6 4s2 3d7 (noble-gas shorthand: [Ar] 3d7 4s2). Its electrons are arranged in shells of 2, 8, 15, 2, with 2 in the outermost shell.
- Is Cobalt a metal or a nonmetal?
- Cobalt is a metal: specifically a transition metal.
- What group and period is Cobalt in?
- Cobalt is in group 9 and period 4 of the periodic table.
- Is Cobalt a solid, liquid, or gas?
- At room temperature, Cobalt is a solid.
Position in the periodic table
Data compiled from Wikipedia, PubChem, and IUPAC. Source.