Symbol | Cu |
Atomic number | 29 |
Group | 11 (Coinage metals) |
Period | 4 |
Block | d |
Classification | Transition Metal |
Appearance | Red-orange metallic luster |
Color | Copper |
Number of protons | 29 p+ |
Number of neutrons | 35 n0 |
Number of electrons | 29 e- |
Phase at STP | Solid |
Density | 8.96 g/cm3 |
Atomic weight | 63.5463 u |
Melting point | 1357.77 K 1084.62 °C 1984.316 °F |
Boiling point | 2835 K 2561.85 °C 4643.33 °F |
Heat of vaporization | 300.5 kJ/mol |
Electronegativity (Pauling Scale) | 1.9 |
Electron affinity | 119.235 kJ/mol |
Oxidation states | −2, 0, +1, +2, +3, +4 (a mildly basic oxide) |
Ionization energies |
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Discovery | Middle East (9000 BC) |
Discovery of copper Copper was probably the first metal mined and crafted by humans. It was originally obtained as a native metal and later from the smelting of ores. Earliest estimates of the discovery of copper suggest around 9000 BC in the Middle East. It was one of the most important materials to humans throughout the Chalcolithic and Bronze Ages. Copper beads dating from 6000 BC have been found in Çatal Höyük, Anatolia and the archaeological site of Belovode on the Rudnik mountain in Serbia contains the world's oldest securely dated evidence of copper smelting from 5000 BC. |