COPPER

TRANSITION ELEMENT: COPPER GROUP

Atomic number:	29
Group numbers:	11
Period:	4
Electronic configuration:	[Ar] 3d¹⁰ 4s¹
Formal oxidation number:	+1 +2
Electronegativities:	1.9
Atomic radius / pm:	127.8
Relative atomic mass:	63.546(3)

Copper has been known since ancient times. The origin of the name comes from the Latin word cuprum meaning the island of Cyprus famed for its copper mines. It is a malleable, ductile, reddish-brown metal, resistant to air and water. Exposed surfaces form greenish carbonate film. Pure copper occurs rarely in nature. It is usually found in sulfides as in chalcopyrite (CuFeS2), coveline (CuS), chalcosine (Cu2S) or oxides like cuprite (Cu2O). Copper is most often used as an electrical conductor and in the manufacture of water pipes. Its alloys are used in jewellery and for coins. The price of 99.9 % pure copper shot is 26.10 € for 500 g.

PHYSICAL PROPERTIES
Density / g dm^-3:	8960	(293 K)
	7940	(m.p.)
Molar volume / cm³mol^-1:	7.09	(293 K)
	8.00	(m.p.)
Electrical resistivity / µΩcm:	1.673	(20 °C)

THERMAL PROPERTIES
Thermal conductivity / W m^-1K^-1:	401
Melting point / °C:	1084.62
Boiling point / °C:	2562
Heat of fusion / kJ mol^-1:	13
Heat of vaporization / kJ mol^-1:	306.7
Heat of atomization / kJ mol^-1:	337.15

IONIZATION ENERGIES
First ionization energy / kJ mol^-1:	745.49
Second ionization energy / kJ mol^-1:	1957.93
Third ionization energy / kJ mol^-1:	3554.64

ABUNDANCE OF ELEMENT
in the atmosphere / ppm:	-
in the Earth's crust / ppm:	75
in the oceans / ppm:	0.003

CRYSTALLOGRAPHIC DATA
Crystal structure:	face-centered cubic
Unit-cell dimensions / pm:	a=361.47
Space group:	Fm3m

ISOTOPES
Isotope	Relative atomic mass	Mass percent (%)
⁶³Cu	62.929601(2)	69.17(3)
⁶⁵Cu	64.927794(2)	30.83(3)

REDUCTION POTENTIALS
Balanced half-reaction	E^o / V
Cu²⁺ + 2e^- → Cu(s)	+0.337
Cu²⁺ + e^- → Cu⁺	+0.153
Cu⁺ + e^- → Cu(s)	+0.521
HCuO₂^- + 3H⁺ + e^- → Cu⁺ + 2H₂O	+1.73
CuO₂^2- + 4H⁺ + e^- → Cu⁺ + 2H₂O	+2.51
HCuO₂^- + 3H⁺ + 2e^- → Cu(s) + 2H₂O	+1.13
CuO₂^2- + 4H⁺ + 2e^- → Cu(s) + 2H₂O	+1.52
2Cu²⁺ + H₂O + 2e^- → Cu₂O(s) + 2H⁺	+0.20
2HCuO₂^- + 4H⁺ + 2e^- → Cu₂O(s) + 3H₂O	+1.78
2CuO₂^2- + 6H⁺ + 2e^- → Cu₂O(s) + 3H₂O	+2.56
CuO + 2H⁺ + e^- → Cu⁺ + H₂O	+0.62
Cu²⁺ + Br^- + e^- → CuBr(s)	+0.64
Cu²⁺ + Cl^- + e^- → CuCl(s)	+0.54
Cu²⁺ + I^- + e^- → CuI(s)	+0.86
CuI(s) + e^- → Cu(s) + I^-	- 0.185
Cu(NH₃)₄²⁺ + e^- → Cu(NH₃)₂⁺ + 2NH₃	- 0.01
Cu(NH₃)₂⁺ + e^- → Cu(s) + 2NH₃	- 0.12
Cu(NH₃)₄²⁺ + 2e^- → Cu(s) + 4NH₃	- 0.07