Ben,
Im pretty sure that my last post, prior to this one, not only made a claim, but then substantiated it with two sources, last time I sat down with a lawyer (divorce) that was enough for a judge. Come to think of it you sound a bit like my ex wife, you have a bee in your bonnet and rather than show why you think your right you just repeat your opinion! Is that you Helen?
For those who couldn't be bothered to follow the link I posted, here is the synopsis;
This term can also be used in a relative sense, considering "noble" as an adjective for the word "metal". A "
galvanic series" is a hierarchy of metals (or other electrically conductive materials, including composites and
semimetals) that runs from
noble to
active, and allows designers to see at a glance how materials will interact in the environment used to generate the series. In this sense of the word,
graphite is more noble than silver and the relative nobility of many materials is highly dependent upon context, as for
aluminium and
stainless steel in conditions of varying
pH.[SUP]
[7][/SUP]
In physics, the definition of a noble metal is even more strict. It is required that the
d-bands of the
electronic structure are filled. Taking this into account, only copper, silver and gold are noble metals, as all d-like band are filled and don't cross the
Fermi level.[SUP]
[8][/SUP] For platinum two d-bands cross the Fermi level, changing its chemical behaviour; it is used as a
catalyst. The different reactivity can easily be seen while preparing clean metal surfaces in
ultra high vacuum; surfaces of "physical defined" noble metals (e.g., gold) are easy to clean and stay clean for a long time, while those of platinum or palladium, for example, are covered by
carbon monoxide very quickly.[SUP]
[9][/SUP]