chuck wrote:

The copper alloys widely used in wires are quite resistant to corrosion.

[...]

73,
Chuck
NT3G

I don't know about corrosion resistance, but the copper wire used in
electrical conductors is very high purity. This is needed since any
contaminants reduce the conductivity. Here are a few quick references:

Copper is made with different purities depending on the application.
The highest grade copper is electrical grade. It is 99.99% pure and
is used for electrical cables because it has the best electrical
conductivity. Electrical grade scrap must never be mixed with any of
the lower purity grades such as plumbing tube scrap. This contains
too much phosphorus which drastically reduces the electrical
conductivity.

The lower grades of scrap can be used to make copper alloys or
chemicals. The copper sulphate you use in your school laboratory has
probably been made with scrap copper.

http://www.schoolscience.co.uk/conte...opch32pg3.html

Copper Facts

Electrical

Copper is the standard benchmark for electrical conductivity. It
conducts electrical current better than any other metal except
silver.

Copper is routinely refined to 99.98% purity (even more pure than
Ivory Soap) before it is acceptable for many electrical
applications.

Number 12 (AWG) copper wire is the most common size used for branch
circuit wiring in buildings. The amount of copper products consumed
in the U.S.A. this past year would make a size 12 wire that could
encircle the Earth 2,630 times or make 140 round trips to the Moon.

http://www.copper.org/education/c-fa...lectrical.html

Regards,

Mike Monett