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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 ...
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 ...
In 1840, Claus, received a substantial amount of platinum ore samples for his studies from the Ural Mountains and the St Petersburg Mint and started working on chemistry and isolation of noble metals, in particular rhodium, iridium, osmium, and to a lesser extent, palladium and platinum. In 1844, he discovered a new chemical element, which he ...
The earliest gold artifacts were discovered at the site of Wadi Qana in the Levant. [13] Silver is estimated to have been discovered in Asia Minor shortly after copper and gold. [14] There is evidence that iron was known from before 5000 BC. [15] The oldest known iron objects used by humans are some beads of meteoric iron, made in Egypt in ...
They presented gifts of gold, silver, porcelain and silk; in return, received such novelties as ostriches, zebras, camels, ivory and giraffes. [61] [62] After the emperor's death, Zheng He led a final expedition departing from Nanking in 1431 and returning to Beijing in 1433. It is likely this last expedition reached as far as Madagascar.
The archaeological finds kept coming for a team of 50 researchers on the Greek island of Evia. But the kicker may have been locating 2,700-year-old altars full of precious jewels and historical ...
Humphry Davy had discovered a few years earlier that a hot platinum wire lit up in a mixture of coal gas and air. [10]) This release of energy from oxidation of the compounds, without flame, and without change in the platinum itself, was a sign of the catalytic property of platinum investigated later by Johann Döbereiner and other chemists.
Fuljenz noted that if you are in the market to sell one of these mirror-proof gold coins, to try and put a $1 from 1983 or 1984 on the market because there are lots of buyers out there.