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  2. Platinum - Wikipedia

    en.wikipedia.org/wiki/Platinum

    Platinum is a chemical element; it has symbol Pt and atomic number 78. It is a dense, malleable, ductile, highly unreactive, precious, silverish-white transition metal. Its name originates from Spanish platina, a diminutive of plata "silver". [7] [8] Platinum is a member of the platinum group of elements and group 10 of the periodic table of ...

  3. Platinum group - Wikipedia

    en.wikipedia.org/wiki/Platinum_group

    The platinum-group metals (PGMs), also known as the platinoids, platinides, ... By 1815, rhodium and palladium had been discovered by William Hyde Wollaston, ...

  4. Metals of antiquity - Wikipedia

    en.wikipedia.org/wiki/Metals_of_antiquity

    The other metals discovered before the Scientific Revolution largely fit the pattern, except for high-melting platinum: Bismuth melts at 272 °C (521 °F) [21] Zinc melts at 420 °C (787 °F), [21] but importantly boils at 907 °C (1665 °F), a temperature below the melting point of silver. Consequently, at the temperatures needed to reduce ...

  5. Discovery of chemical elements - Wikipedia

    en.wikipedia.org/wiki/Discovery_of_chemical_elements

    Wollaston discovered and isolated it from crude platinum samples from South America. [116] 53 Iodine: 1811 B. Courtois: 1811 B. Courtois Courtois discovered it in the ashes of seaweed. [117] The name iode was given in French by Gay-Lussac and published in 1813. [52] Davy gave it the English name iodine in 1814. [52] 3 Lithium: 1817 A. Arfwedson ...

  6. William Hyde Wollaston - Wikipedia

    en.wikipedia.org/wiki/William_Hyde_Wollaston

    Chemical analysis related to the process of purifying platinum led Wollaston to discover the elements palladium (symbol Pd) in 1802 and rhodium (symbol Rh) in 1804. [1] When Anders Gustav Ekeberg discovered tantalum in 1802 Wollaston declared the new element identical with niobium (then known as columbium).

  7. Precious metal - Wikipedia

    en.wikipedia.org/wiki/Precious_metal

    Other precious metals include the platinum group metals: ruthenium, rhodium, palladium, osmium, iridium, and platinum, of which platinum is the most widely traded. [1] The demand for precious metals is driven not only by their practical use but also by their role as investments and a store of value. Historically, precious metals have commanded ...

  8. AOL Plans - AOL Help

    help.aol.com/articles/aol-advantage-plans

    Tech Plus by AOL will provide around-the-clock tech support for all your devices coupled with computer and digital data protection services. • Tech Plus by AOL - Platinum - Tech Plus Platinum includes top of the line products to help protect your identity, personal data and devices, so that you have more control over your digital life.

  9. International Prototype of the Kilogram - Wikipedia

    en.wikipedia.org/wiki/International_prototype_of...

    The only three verifications occurred in 1889, 1948, and 1989. For instance, the US owns five 90% platinum / 10% iridium (Pt‑10Ir) kilogram standards, two of which, K4 and K20, are from the original batch of 40 replicas distributed in 1884. [Note 4] The K20 prototype was designated as the primary national standard of mass for the US. Both of ...