Noble Metal
The noble metals are metals that are resistant to corrosion and oxidation in moist air, unlike most base metals. They tend to be precious, often due to their rarity in the Earth's crust. The noble metals are considered to be (in order of increasing atomic number) ruthenium, rhodium, palladium, silver, osmium, iridium, platinum, and gold.
Other sources include mercury or even rhenium as a noble metal. On the other hand, titanium, niobium, and tantalum are not included as noble metals despite the fact that they are very resistant to corrosion. Noble metals should not be confused with precious metals (although many noble metals have high value).
Read more about Noble Metal: Introduction, Electrochemistry
Famous quotes containing the words noble and/or metal:
“Rereading this novel today, replaying the moves of its plot, I feel rather like Anderssen fondly recalling his sacrifice of both Rooks to the unfortunate and noble Kieseritsky—who is doomed to accept it over and over again through an infinity of textbooks, with a question mark for monument.”
—Vladimir Nabokov (1899–1977)
“We are supposed to be the children of Seth; but Seth is too much of an effete nonentity to deserve ancestral regard. No, we are the sons of Cain, and with violence can be associated the attacks on sound, stone, wood and metal that produced civilisation.”
—Anthony Burgess (b. 1917)