Copper
transition metal · period 4 · group 11 (coinage metals) · d-block
Copper is a chemical element with the symbol Cu (from Latin: cuprum) and atomic number 29. It is a soft, malleable, and ductile metal with very high thermal and electrical conductivity.
What the numbers say
At standard temperature and pressure Copper is a solid, sitting in period 4, group 11 of the d-block.
Its melting point of 1358 K (1085 °C) is the 44th highest of the 110 elements with a measured value — mid-range among the elements.
At 8.96 g/cm³ it is the 33rd densest of 96 elements with a quoted density.
Pauling electronegativity is 1.9. Paired with oxygen (3.44) that is a difference of 1.54, which puts the bond polar covalent — oxides here tend to be semiconducting or refractory rather than salt-like.
In the solid state it takes a face-centered cubic structure — FCC packing gives 12 independent slip systems, which is why FCC metals are the ductile, formable ones.
It is reported in 4 oxidation states (1, 2, 3, 4), which sets how many distinct compounds and phases it can form.
First identified in c. 8000 BCE.
Crystal structure
Solid Copper adopts a Face-centered Cubic arrangement, in the Cubic (isometric) system — axes a = b = c, angles α = β = γ = 90°. Symmetry controls the anisotropy of stiffness and thermal expansion, and the available slip systems set how far the metal deforms before it fractures.
Where copper shows up in engineering materials
1 entry in the materials library names it directly:
- Copper Cu-ETP (C11000) — Pure copper
Crystallographic examples
Copper or one of its compounds is a textbook example for these crystal systems:
- Cubic (isometric) — Cu, Al, Fe-α (BCC), NaCl, diamond, spinel MgAl₂O₄
- Triclinic — Kaolinite, albite, CuSO₄·5H₂O
Check it against computed structures
The structure search queries the Materials Project, OQMD and the Open Materials Database for computed crystal structures containing Cu — with DFT formation energy, hull stability and band gap where the provider publishes them.
K 2 · L 8 · M 18 · N 1
Properties
| Atomic number | 29 |
|---|---|
| Atomic mass | 63.5463 u |
| Series | transition metal |
| Group | 11 |
| Period | 4 |
| Block | d-block |
| Phase at STP | Solid |
| Density | 8.96 g/cm³ |
| Melting point | 1357.77 K (1085 °C) |
| Boiling point | 2835 K (2562 °C) |
| Electronegativity (Pauling) | 1.9 |
| Electron configuration | [Ar] 3d¹⁰ 4s¹ |
| Crystal structure | Face-centered Cubic |
| Oxidation states | 1,2,3,4 |
| Discovered | c. 8000 BCE |
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See Cu in context with all 118 elements.
Working with copper in a real design?
Ask the materials chat how Cu behaves in your alloy system, what it does to weldability, and which grades to look at — with the source of every number named.