From Wikipedia, the free encyclopedia
-
| |
| General |
| Name, Symbol,
Number |
copper, Cu, 29 |
| Chemical series |
transition metals |
| Group, Period, Block |
11, 4, d |
| Appearance |
metallic brown
 |
| Atomic mass |
63.546(3)
g/mol |
| Electron configuration |
[Ar]
3d10 4s1 |
| Electrons per shell |
2, 8, 18, 1 |
| Physical
properties |
| Phase |
solid |
| Density (near r.t.) |
8.96 g?cm?3 |
| Liquid density at m.p. |
8.02 g?cm?3 |
| Melting point |
1357.77 K
(1084.62 ?C, 1984.32 ?F) |
| Boiling point |
2835 K
(2562 ?C, 4643 ?F) |
| Heat
of fusion |
13.26 kJ?mol?1 |
| Heat
of vaporization |
300.4 kJ?mol?1 |
| Heat capacity |
(25 ?C) 24.440 J?mol?1?K?1 |
Vapor pressure
| P/Pa |
1 |
10 |
100 |
1 k |
10 k |
100 k |
| at T/K |
1509 |
1661 |
1850 |
2089 |
2404 |
2836 |
|
| Atomic
properties |
| Crystal structure |
cubic face centered |
| Oxidation states |
2, 1
(mildly basic oxide) |
| Electronegativity |
1.90 (Pauling scale) |
Ionization energies
(more) |
1st: 745.5 kJ?mol?1 |
| 2nd: 1957.9 kJ?mol?1 |
| 3rd: 3555 kJ?mol?1 |
| Atomic radius |
135
pm |
| Atomic radius (calc.) |
145
pm |
| Covalent radius |
138
pm |
| Van der Waals radius |
140 pm |
| Miscellaneous |
| Magnetic ordering |
diamagnetic |
| Electrical resistivity |
(20 ?C) 16.78 n??m |
| Thermal conductivity |
(300 K) 401 W?m?1?K?1 |
| Thermal
expansion |
(25 ?C) 16.5 ?m?m?1?K?1 |
| Speed of sound (thin
rod) |
(r.t.) (annealed)
3810 m?s?1 |
| Young's modulus |
130 GPa |
| Shear modulus |
48 GPa |
| Bulk modulus |
140 GPa |
| Poisson ratio |
0.34 |
| Mohs
hardness |
3.0 |
| Vickers hardness |
369 MPa |
| Brinell hardness |
874 MPa |
| CAS registry number |
7440-50-8 |
| Notable
isotopes |
| |
| References |
Copper is a chemical element in the
periodic table that has
the symbol Cu (L.: Cuprum) and atomic
number 29. It is a ductile metal with excellent electrical conductivity,
and finds extensive use as an electrical conductor, as a building
material, and as a component of various alloys.
Notable characteristics
Copper is a reddish-coloured metal, with a high electrical and
thermal conductivity (among pure metals at room temperature, only
silver has a higher
electrical conductivity). In oxidation is mildly basic. Copper has its
characteristic colour because it reflects red and orange light
and absorbs other frequencies in the visible spectrum, due to
its band structure. Contrast
this with the optical properties of silver, gold and aluminium.
Copper occupies the same family of the periodic table as silver
and gold, hence it shares many characteristics with these metals.
All have very high thermal and electrical conductivity. All are
malleable metals. Gold and copper are the only colored metallic
elements besides caesium, the alkali metal
of period six.
Copper is insoluble in water (H2O) as well as in isopropanol,
or isopropyl alcohol.
There are two stable isotopes, 63Cu and 65Cu,
along with a couple of dozen radioisotopes. The vast majority
of radioisotopes have half lives on the order of minutes or less;
the longest lived, 64Cu, has a half life of 12.7 hours,
with two decay modes, leading to two separate products.
There are numerous alloys of copper—speculum metal is a copper/tin
alloy, brass is a copper/zinc alloy, and bronze is a copper/tin alloy. Monel metal is a copper/nickel alloy, also
called cupronickel. While the metal
"bronze" usually refers to copper/tin alloys, it also is a generic
term for any alloy of copper, such as aluminium bronze, silicon
bronze, and manganese bronze.
The purity of copper is expressed as 4N for 99.9999% pure or
7N for 99.9999999% pure. The numeral gives the number of nines
after the decimal point.
Applications
Copper exists as a
metallically bonded substance,
allowing it to have a wide variety of metallic properties.
Copper is malleable and ductile, a good conductor of heat and, when very pure,
a good conductor of electricity.
It is used extensively, in products such as:
