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The blue plaque for Smithson Tennant in Finkle Street, Selby, North Yorkshire. Smithson Tennant FRS (30 November 1761 [1] – 22 February 1815 [2]) was an English chemist.He is best known for his discovery of the elements iridium and osmium, which he found in the residues from the solution of platinum ores in 1803.
The density of osmium is slightly greater than that of iridium; the two are so similar (22.587 versus 22.562 g/cm 3 at 20 °C) that each was at one time considered to be the densest element. Only in the 1990s were measurements made accurately enough (by means of X-ray crystallography) to be certain that osmium is the denser of the two. [11] [15]
(The Ebers papyrus was written c. 1550 BC, but is believed to have been copied from earlier texts.) [25] [26] Designated as one of the two elements of which all metals are composed in the sulfur-mercury theory of metals, first described in pseudo-Apollonius of Tyana's Sirr al-khaliqa ('Secret of Creation') and in the works attributed to Jabir ...
Group 8 is a group (column) of chemical elements in the periodic table.It consists of iron (Fe), ruthenium (Ru), osmium (Os) and hassium (Hs). [1] " Group 8" is the modern standard designation for this group, adopted by the IUPAC in 1990. [1]
Osmium hexafluoride is one of the 17 known binary hexafluorides, which can be made by the direct reaction of osmium metal exposed to an excess of elemental fluorine gas at 300 °C. It is a yellow crystalline solid that melts at 33.4 °C and boils at 47.5 °C. [24]
Iridium is one of the characteristic elements of extraterrestrial rocks, and, along with osmium, can be used as a tracer element for meteoritic material in sediment. [ 71 ] [ 72 ] For example, core samples from the Pacific Ocean with elevated iridium levels suggested the Eltanin impact of about 2.5 million years ago.
The Christmas Eve stowaway who boarded a Delta Air Lines flight to Hawaii slipped past both a TSA ID check and a gate agent with no ticket, according to public records obtained by CNN.
The earliest-known metals—common metals such as iron, copper, and tin, and precious metals such as silver, gold, and platinum—are heavy metals. From 1809 onward, light metals , such as magnesium , aluminium , and titanium , were discovered, as well as less well-known heavy metals including gallium , thallium , and hafnium .