Copper
[Ar] 3d¹⁰ 4s¹ · 2 · 8 · 18 · 1
The first metal humans learned to work, and still the best affordable conductor after silver. Copper named the Bronze Age and the island of Cyprus, and no electrical grid runs without it.
3D model
Bohr model: nucleus and electron shells from the real configuration. Valence electrons are highlighted.
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Atomic properties
- Atomic number
- 29
- Atomic mass
- 63.546 а.е.м.
- Electron configuration
- [Ar] 3d¹⁰ 4s¹
- Electrons per shell
- 2 · 8 · 18 · 1
- Block
- d-block
- Group
- Copper group
- Period
- 4
- Electronegativity (Pauling)
- 1.9
- Electronegativity (Allen)
- 1.85
- Atomic radius
- 145 pm
- Covalent radius
- 132 pm
- Van der Waals radius
- 140 pm
- Ionisation energy 1
- 745.5 kJ/mol
- Ionisation energy 2
- 1 957.9 kJ/mol
- Ionisation energy 3
- 3 555 kJ/mol
- Ionisation energy 4
- 5 536 kJ/mol
- Ionisation energy 5
- 7 700 kJ/mol
- Electron affinity
- 118.4 kJ/mol
- Common oxidation states
- +1, +2
- Oxidation states
- -2, +1, +2, +3, +4
Physical properties
- State at 25 °C
- solid
- Density
- 8.96 g/cm³
- Melting point
- 1 357.77 K · 1 084.6 °C
- Boiling point
- 2 835 K · 2 561.9 °C
- Speed of sound
- 3 810 m/s
Thermal properties
- Heat of fusion
- 13.26 kJ/mol
- Heat of vaporisation
- 300.4 kJ/mol
- Specific heat capacity
- 0.385 J/(g·K)
- Thermal conductivity
- 401 W/(m·K)
Mechanical properties
- Young's modulus
- 130 GPa
- Shear modulus
- 48 GPa
- Bulk modulus
- 140 GPa
- Poisson ratio
- 0.34
- Mohs hardness
- 3
- Brinell hardness
- 874 MPa
Electrical and magnetic properties
- Electrical resistivity
- 16.78 nΩ·m
- Magnetic ordering
- diamagnetic
- Curie point
- no data
- Néel point
- no data
- Superconducting point
- no data
Crystal structure
- Crystal structure
- face-centred cubic (fcc)
- Lattice constants
- a = 361.49 pm
Abundance
- In the crust
- 60 mg/kg
- In the ocean
- 0.00025 mg/L
- In the universe
- 60 mg/kg
- In the human body
- 1 mg/kg
Isotopes
| Isotope | Abundance | Half-life | Decay mode |
|---|---|---|---|
| 63Cu | 69.15 % | stable | — |
| 65Cu | 30.85 % | stable | — |
Two stable isotopes. Copper-64 is used in PET imaging and copper-67 in targeted radionuclide therapy.
Discovery
- Year of discovery
- known since antiquity
- Discovered by
- known since antiquity
- Where
- no data
- Origin of the name
- from Latin cuprum, metal of Cyprus
History
Copper artefacts date from the ninth millennium BCE. Alloyed with tin it gave bronze and an entire era. Latin cuprum comes from aes cyprium, Cyprian ore: Cyprus was Rome's main source.
Where it occurs
60 mg/kg of the crust. It occurs native, but is mined industrially from sulfides — chalcopyrite and bornite. Chile is the largest producer.
How it is produced
Flotation to concentrate, smelting to matte, converting to blister copper and electrolytic refining to 99.99 %. A large share comes from scrap.
Role in living things
An essential micronutrient: copper sits in cytochrome c oxidase of the respiratory chain. In molluscs and arthropods haemocyanin carries oxygen on copper, which is why their blood is blue.
Safety
Excess copper is hepatotoxic; Wilson's disease is an inherited failure to excrete it. Copper ions are lethal to algae and bacteria, which is the basis of its antimicrobial action.
Uses
- Wiring and motor windings — roughly half of consumption
- Roofing and plumbing: copper lasts centuries
- Alloys: brass with zinc, bronze with tin, cupronickel with nickel
- Heat exchangers and radiators
- Antimicrobial surfaces in hospitals
Curiosities
- The Statue of Liberty is clad in copper 2.4 mm thick; the green is a patina of basic carbonates.
- Copper kills bacteria and viruses on contact within hours — an effect known since ancient Egypt.
- Brass and bronze are both copper alloys, with zinc and tin respectively.
- Only silver conducts better than copper, and silver costs a hundred times more.