Cobalt is a magnetic metal used in magnets and alloys that retain strength at high temperatures. Its compounds also produce blue colors in glass and ceramics. In living systems, cobalt forms part of vitamin B12, connecting metal chemistry to both engineered and biological materials.
FROM ELEMENT TO APPLICATION
AN ELEMENT IN CONTEXT
What must be demonstrated before a cobalt alloy can serve in a hot turbine component?
Cobalt-containing engineering alloys
FOLLOW THIS RELATIONSHIP
Define the turbine environment
A turbine component faces heat and mechanical loading together, so its material must be judged against the combined demands of that particular location.
Explore the model (optional)
CoFORM → INTERACTION → CONSEQUENCE
Follow the explanation in either direction. These are authored steps, not a physical clock.
Atomic identity, reference properties and structure models
INTERACTIVE 3D27 visible sites
An electron censusDrag to rotate · scroll or pinch to zoom
[Ar] 3d7 4s2. Grouping electrons by principal shell connects the neutral-atom configuration to periodic-table patterns.
What this representation means
A three-dimensional counting diagram. Dots are count markers, not measured electron positions; spherical placement and spacing are arbitrary. There are no electron trajectories here. Orbitals describe quantum states.
Cobalt-bearing materials colored glass and ceramics before the element was recognized. During the 1730s Brandt investigated an associated with copper workings and argued that it contained a distinct metal. His 1739 publication did not bring immediate acceptance. Ores and early samples contained several elements, creating an analytical challenge: investigators had to separate their effects before the disputed identity.
Antiquity
Blue materials made
Cobalt-containing substances colored glass and ceramic objects before elemental identification.
1739
Results published
Brandt published his investigation establishing cobalt as a distinct metallic constituent.
Cobalt occurs in such as cobaltite and erythrite and often accompanies ores containing nickel, copper, or other metals. It can therefore be recovered alongside another metal rather than from an isolated cobalt-only deposit. Cobalt also occurs in meteorites, connecting terrestrial mineral chemistry with extraterrestrial material.
Cobalt is a hard metal with magnetic behavior and more than one possible structure. Its properties depend on structure, temperature, and the elements combined with it. Cobalt salts can produce strong colors, illustrating the difference between the appearance of a metal and the behavior of its compounds.
Each section links its supporting references. Descriptions and diagrams were authored for this atlas. Source checks completed. Source checks dated 2026-09-06.
CITE THIS PAGE
Family labels and the group-3 layout are teaching conventions. A table position does not establish an unknown bulk property. Electronic configurations refer to neutral atoms; ions and material environments require their own account.
Read each reference property together with its units, conditions and the reference information below.
Not yet recorded: electron affinity, second ionization energy, ground-state term symbol, van der waals radius, thermal conductivity, specific heat capacity, electrical resistivity, crystal structure, lattice parameter a, space group, abundance in seawater, abundance in the universe, annual production, supply-risk listing, hazard classification, biological role, cas registry number, pubchem cid, wikidata item. These families are declared and awaiting an ingestion run against the source each names; they are listed here rather than shown as empty rows.
Physical
Intended reference: CRC Handbook of Chemistry and Physics · CRC Press
Phase at 20 °C
solid
293.15 K, 101.325 kPa
Melting point in K
1768 K
at standard pressure unless noted
Boiling point in K
3200 K
101.325 kPa
Density in g/cm³
8.9 g/cm³
solids and liquids at 293 K; gases at 273 K and 101.325 kPa
Atomic and electronic
Intended reference: Pauling electronegativity scale · Widely tabulated; original in The Nature of the Chemical Bond
Electronegativity in Pauling
1.88 Pauling
Pauling scale
First ionization energy in kJ/mol
760.4 kJ/mol
gas-phase neutral atom, ground state
Covalent radius in pm
126 pm
single-bond covalent radius
Common oxidation states
+2, +3
states met in ordinary compounds; not exhaustive
Occurrence and identity
Intended reference: CRC Handbook of Chemistry and Physics · CRC Press
Abundance in the crust in mg/kg
25 mg/kg
upper continental crust, mass fraction
Has stable isotopes
Yesderived
Discovery year in CE
1735 CEderived
WHERE IT SITS AMONG ITS NEIGHBORS
Electronegativity across period 4
Co 1.88 Pauling · Cobalt
Electronegativity across period 4. Exact values.
K
0.82
Ca
1
Sc
1.36
Ti
1.54
V
1.63
Cr
1.66
Mn
1.55
Fe
1.83
Co
1.88
Ni
1.91
Cu
1.9
Zn
1.65
Ga
1.81
Ge
2.01
As
2.18
Se
2.55
Br
2.96
Kr
3
Electronegativity down group 9
Co 1.88 Pauling · Cobalt
Electronegativity down group 9. Exact values.
Co
1.88
Rh
2.28
Ir
2.2
The trend uses the same reference-property values as the periodic table. Elements with no recorded value are left out of the line rather than drawn at zero.
