ELEMENTLE

Element 29 · Transition Metal

Copper

Period 4 · Group 11

Copper is a chemical element with symbol Cu (from Latin:cuprum) and atomic number 29. It is a soft, malleable and ductile metal with very high thermal and electrical conductivity. A freshly exposed surface of pure copper has a reddish-orange color.

Three reasons Copper stands out

  1. 1

    Used in electrical wiring.

  2. 2

    It has natural antimicrobial properties that kill bacteria and viruses on contact.

  3. 3

    The Statue of Liberty gets its green colour from a thin layer of oxidised compounds of this metal.

The metal that wired civilization

Copper carries electricity efficiently while remaining ductile enough to draw into long wires. Exposure gradually creates protective green and brown surface compounds, as seen on old roofs and statues. Long before electrical grids, copper and its alloy bronze helped define entire eras of tools and art.

Copper at a glance
Atomic number / protons29
SymbolCu
Family (Elementle)Transition Metal
Classification (PubChem)Transition metal
Period4
Group11
Atomic mass (u)63.55
Standard stateSolid
Electron configuration[Ar]4s1 3d10
Reported oxidation states+2, +1
Electronegativity (Pauling)1.9
Atomic radius (pm)140
First ionization energy (eV)7.726
Electron affinity (eV)1.228
Density (g/cm³)8.933
Melting point1357.77 K (1,084.62 °C)
Boiling point2835 K (2,561.85 °C)
Discovery (PubChem)Known since antiquity

Values are reference data, not a specification for every temperature, pressure, or allotrope. Unknown properties are left unavailable. Superheavy-element predictions remain uncertain.

Sources & further reading

PubChem: Copper · Copper on Wikipedia

The introduction and original editorial story are adapted from Wikipedia contributors via Periodic-Table-JSON. Element descriptions and their adaptations are available under CC BY-SA 3.0. Numerical attributes use the PubChem periodic-table dataset, retrieved September 22, 2026.