1. Basic parameters
Atomic number: 29
Atomic weight: 63.546
Crystal structure: face-centred cubic (FCC)
Density: 8.96 g/cm³ (20°C)
2. Appearance and colour
Colour: red-orange (pure copper), green copper basic carbonate (copper green) formed after surface oxidation.
Lustre: metallic luster.
3. Thermal properties
Melting point: 1084.62°C
Boiling point: 2562°C
Specific heat capacity: 0.385 J/(g-K) (25°C)
Thermal conductivity: 401 W/(m-K) (20°C)
Second only to silver, it is an excellent thermal conductivity material.
Coefficient of thermal expansion: 16.5 × 10-⁶ /K (25°C)
4. Electrical properties
Electrical conductivity: 5.96 × 10⁷ S/m (20°C)
Pure copper is second only to silver in electrical conductivity and is widely used in wires, cables and electronic components.
Resistivity: 1.68 × 10-⁸ Ω-m (20°C)
5. Mechanical properties
Hardness: approximately 3.0 on the Mohs scale (pure copper is softer and can be increased by cold working or alloying).
Ductility: extremely high, can be drawn into fine wires (copper wire) or pressed into thin sheets (copper foil).
Tensile strength: 200-250 MPa (annealed copper), up to 300-400 MPa after cold working.
6. Magnetic properties
Magnetic properties: antimagnetic (weakly repulsive magnetic field), not ferromagnetic.
7. Other properties
Corrosion resistance: stable in dry air, easy to oxidise in humid environment to produce copper green (alkaline copper carbonate).
Machinability: easy to cut, forge, roll and weld.
Application correlation
High electrical/thermal conductivity: used in electrical wiring, heat sinks, electronic devices.
Ductility: Used in piping, decorative materials.
Corrosion resistance: used for roofing, ship components (often alloyed with zinc and tin such as brass and bronze).
The properties of copper can be further optimised by alloying (e.g. with zinc, tin, nickel, etc.) to meet different industrial needs.
