Periodic table › Copper
1. Identity and classification
Red-orange metallic solid with high ductility, malleability, and thermal/electrical conductivity
- Name and symbol
- Copper (Copper) · Cu
- Atomic number
- 29
- Relative atomic weight / mass number
- 63.546 ± 0.003
- Group · period · block
- 11 · 4 · d
- Category
- Transition Metal
- State near room temperature
- Solid
- Stable isotopes
- At least one stable isotope
- CAS number
- 7440-50-8
Square brackets [A] indicate a representative isotope mass number, not an average atomic weight. Neutron counts differ between isotopes.
2. Atomic structure and electron configuration
- Protons · electrons in a neutral atom
- 29 · 29
- Neutrons in reference isotope
- 34 (63Cu)
- Full electron configuration
1s² 2s² 2p⁶ 3s² 3p⁶ 3d¹⁰ 4s¹- Abbreviated configuration
[Ar]4s¹ 3d¹⁰- Electrons per shell
- 2, 8, 18, 1
- Listed oxidation states
- +2, +1
- Electronegativity
- 1.9 (Pauling)
- First ionization energy
- 745.446 kJ/mol · 7.726 eV
- Electron affinity
- 118.484 kJ/mol
- Covalent radius
- 132 pm
- van der Waals radius
- 140 pm
Configurations of superheavy elements may include theoretical predictions. Different definitions of atomic radius are not interchangeable.
3. Physical and thermal properties
- Density
- 8.933 g/cm³
- Melting point
- 1357.77 K · 1084.62 °C · 1984.316 °F
- Boiling point
- 2835 K · 2561.85 °C · 4643.33 °F
- Crystal structure
- FCC
- Specific heat
- 0.385 J/(g·K)
- Thermal conductivity
- 401 W/(m·K)
- Enthalpy of fusion
- 13.26 kJ/mol
- Enthalpy of vaporization
- 300.4 kJ/mol
- Magnetic ordering
- Diamagnetic
- Mohs hardness
- 3
- Speed of sound
- 3810 m/s
Density and structure depend on temperature, pressure and allotrope. 25°C is a room-temperature reference, not STP. Unestablished values are not zero.
4. Chemical behavior and compounds
Copper does not liberate hydrogen from dilute non-oxidizing acids; oxidizing acids can dissolve it.
Selected compounds: CuSO₄·5H₂O (Blue vitriol / Copper(II) sulfate) · CuO (Copper(II) oxide) · Cu₂O (Cuprite) · CuCl₂
Reaction reference
Copper oxidizes slowly in air; surface products depend on environmental conditions.
No reaction with ordinary cold water.
5. Isotopes
| Isotope | Status | Natural abundance | Half-life |
|---|---|---|---|
| 63Cu | Stable | 69.15% | Stable |
| 64Cu | Radioactive | — | 12.7006 h |
| 65Cu | Stable | 30.85% | Stable |
Half-life units: s seconds, m minutes, h hours, d days, Y years. A dash means no natural-abundance value is given, not zero. Listed records are selected ground states; metastable states are distinct.
6. Discovery and occurrence
- Discovery
- Known since antiquity; no exact discovery year
- Scientists associated with discovery
- Known since antiquity
- Location
- Middle East & Cyprus
- Origin
- Natural
- Listed crustal abundance
- 60 ppm
Minerals and naming reference
Chalcopyrite (CuFeS₂), Bornite (Cu₅FeS₄), Chalcocite (Cu₂S), Malachite, Azurite, Native Copper
From Latin 'aes Cyprium' (metal of Cyprus), shortened to 'cuprum'
7. Applications
Household electrical wiring, plumbing pipes, brass and bronze hardware, coins, cookware
Detailed applications by field
- everyday
- Household electrical wiring, plumbing pipes, brass and bronze hardware, coins, cookware
- industry
- Brass (Cu-Zn) and bronze (Cu-Sn) alloys, industrial heat exchangers, marine anti-fouling hulls
- electronics
- Printed circuit board (PCB) traces, microprocessor interconnects, high-frequency coaxial cables, electromagnets
- medicine
- Antimicrobial copper touch surfaces in hospitals, copper intrauterine devices (IUDs)
- energy
- EV traction motors, solar inverter busbars, high-voltage power transmission grids, wind generators
- aerospace
- Regeneratively cooled liquid rocket engine combustion chambers (e.g., CuCrZr alloys)
- agriculture
- Bordeaux mixture and copper sulfate fungicides for vineyards and orchards
- science
- Cu K-alpha X-ray tubes for X-ray crystallography; YBCO high-temperature cuprate superconductors
8. Biological role and safety
Hazard depends on the isotope, chemical form, dose and exposure route.
Elemental substances, ions, compounds and radioisotopes can have different health effects. This is an educational reference; laboratory work requires the material safety data sheet and trained supervision.
Biological role reference
Essential cofactor in cytochrome c oxidase (respiration), superoxide dismutase (antioxidant defense), and tyrosinase; forms hemocyanin oxygen carrier in mollusks and arthropods.