ElementsWhat is copper?
Copper is a reddish metal and one of the first metals people ever used. It carries electricity and heat better than any metal except silver. In air it slowly turns green.
What is copper used for?
Electrical wiring and motors, water pipes, cooking vessels, coins, and the alloys brass and bronze.
Where the name comes from
From Cyprus, the island where the Romans mined it. The symbol Cu comes from cuprum, its Latin name.
Key facts
- Symbol
- Cu
- Atomic number
- 29
- Atomic mass
- 63.55 u
- Family
- Transition metal
- Period
- 4
- Group
- 11
- Block
- d
- State at room temperature
- Solid
- Melting point
- 1,085 °C (1,358 K, 1,984 °F)
- Boiling point
- 2,562 °C (2,835 K, 4,643 °F)
- Density
- 8.93 g/cm³
- Electrons per shell
- 2, 8, 18, 1
- Electron configuration
- [Ar]4s1 3d10
- Common oxidation states
- +2, +1
- Electronegativity (Pauling)
- 1.9
- First ionisation energy
- 7.726 eV
- Electron affinity
- 1.228 eV
- Atomic radius (van der Waals)
- 140 pm
- Discovered
- Known since ancient times
Place in the periodic table
Copper is element number 29. It sits in period 4 (row 4) of the periodic table, in group 11 (column 11), and belongs to the d-block. Just before it comes nickel (28), and just after it comes zinc (30). In the same column, silver is below it. Elements in one column tend to behave alike.
Family: Transition metals.
Physical properties
At room temperature copper is a solid. It melts at 1,085 °C and boils at 2,562 °C, so it stays liquid over a range of 1,477 degrees. Its density is 8.93 grams per cubic centimetre, so a one-litre block would weigh about 8.93 kilograms. By density it ranks 32nd among the 96 elements with a measured value.
Inside the atom
An atom of copper has 29 protons in its nucleus and, when neutral, 29 electrons around it. The electrons are arranged in 4 shells: 2, 8, 18, 1. The outermost shell holds 1 electron. Written in full, the electron configuration is [Ar]4s1 3d10.
Its electronegativity on the Pauling scale is 1.9. This number shows how strongly an atom pulls shared electrons towards itself: fluorine, the strongest, is 3.98. Removing one electron from an atom takes 7.726 electronvolts (about 745 kilojoules per mole). One mole of copper weighs 63.55 grams, so a single gram contains about 9.48 × 1021 atoms.
The ring picture is a simple model that only counts the electrons in each shell. Real atoms do not look like this.
Next steps
- Work out the weight of a compound that contains copper with the molar mass calculator.
- Compare it with every other element in the sortable list.
- Test yourself with the symbol quiz.
Figures on this page are from PubChem (U.S. National Library of Medicine), as downloaded on 11 November 2026. See About and data sources.