Quick answerCobalt (Co) is a transition metal with atomic number 27 and an atomic mass of 58.933 (2023), in group 9, period 4. It was discovered by Georg Brandt in 1735. It is used for lithium-ion batteries and superalloys for jet engines. Its electron configuration is [Ar] 3d7 4s2.
Cobalt colours glass a deep blue, hardens cutting tools, and powers the lithium-ion batteries in phones and electric cars.
Key facts
| Symbol | Co |
|---|---|
| Atomic number | 27 |
| Atomic mass | 58.933 (IUPAC standard atomic weight, 2023) |
| Category | transition metal |
| Group | 9 |
| Period | 4 |
| Block | d-block |
| Electron configuration | [Ar] 3d7 4s2 |
| Discovered | Georg Brandt, 1735 |
| Uses | lithium-ion batteries, superalloys for jet engines, blue glass and ceramics, magnets, catalysts |
Quick quiz
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Keep exploring
- Periodic table — all 118 elements
- Scandium (Sc) — another transition metal, atomic number 21
- Titanium (Ti) — another transition metal, atomic number 22
- Vanadium (V) — another transition metal, atomic number 23
- Chromium (Cr) — another transition metal, atomic number 24
- Manganese (Mn) — another transition metal, atomic number 25
- Iron (Fe) — another transition metal, atomic number 26
- Nickel (Ni) — another transition metal, atomic number 28
- Copper (Cu) — another transition metal, atomic number 29
- Zinc (Zn) — another transition metal, atomic number 30
- Yttrium (Y) — another transition metal, atomic number 39
- All transition metal elements — on the periodic table
Sources & last updated
- CIAAW — Standard Atomic Weights
- PubChem Periodic Table
- Wikipedia — Timeline of chemical element discoveries
Last updated: . Figures are shown with their year; where sources disagree, the value is left out rather than estimated.