The first transuranium element (element with atomic number greater than 92) discovered was neptunium in 1940. Since 1999 claims for the discovery of new elements have been considered by the IUPAC/IUPAP Joint Working Party. As of January 2016, all 118 elements have been confirmed as discovered by IUPAC. The discovery of element 112 was acknowledged in 2009, and the name copernicium and the atomic symbolCn were suggested for it.[32] The name and symbol were officially endorsed by IUPAC on 19 February 2010.[33] The heaviest element that is believed to have been synthesized to date is element 118, ununoctium, on 9 October 2006, by the Flerov Laboratory of Nuclear Reactions in Dubna, Russia.[12][34] Element 117 was the latest element claimed to be discovered, in 2009.[35] IUPAC officially recognized flerovium andlivermorium, elements 114 and 116, in June 2011 and approved their names in May 2012.[36] In December 2015, IUPAC further recognized elements 113, 115, 117 and 118, and the official names of those elements will be decided thereafter.[37]
Sunday, January 10, 2016
FOUR new elements (inc Japonicium and Moscovium?) - Periodic Table of Videos
The first transuranium element (element with atomic number greater than 92) discovered was neptunium in 1940. Since 1999 claims for the discovery of new elements have been considered by the IUPAC/IUPAP Joint Working Party. As of January 2016, all 118 elements have been confirmed as discovered by IUPAC. The discovery of element 112 was acknowledged in 2009, and the name copernicium and the atomic symbolCn were suggested for it.[32] The name and symbol were officially endorsed by IUPAC on 19 February 2010.[33] The heaviest element that is believed to have been synthesized to date is element 118, ununoctium, on 9 October 2006, by the Flerov Laboratory of Nuclear Reactions in Dubna, Russia.[12][34] Element 117 was the latest element claimed to be discovered, in 2009.[35] IUPAC officially recognized flerovium andlivermorium, elements 114 and 116, in June 2011 and approved their names in May 2012.[36] In December 2015, IUPAC further recognized elements 113, 115, 117 and 118, and the official names of those elements will be decided thereafter.[37]
11: Sodium Tile (12 Days of Christmas with chemistry)
Metallic sodium is mainly used for the production of sodium borohydride, sodium azide, indigo, and triphenylphosphine. Previous uses were for the making of tetraethyllead and titanium metal; because applications for these chemicals were discontinued, the production of sodium declined after 1970.[19] Sodium is also used as an alloying metal, an anti-scaling agent,[45] and as a reducing agent for metals when other materials are ineffective. Note the free element is not used as a scaling agent, ions in the water are exchanged for sodium ions. Sodium vapor lamps are often used for street lighting in cities and give colours ranging from yellow-orange to peach as the pressure increases.[46] By itself or with potassium, sodium is a desiccant; it gives an intense blue colouration with benzophenone when the desiccate is dry.[47] In organic synthesis, sodium is used in various reactions such as the Birch reduction, and the sodium fusion test is conducted to qualitatively analyse compounds.[48] Lasers emitting light at the D line, utilising sodium, are used to create artificial laser guide stars that assist in the adaptive optics for land-based visible light telescopes.
10: Thorium and Osmium (12 Days of Christmas with chemistry)
Thorium is a chemical element with symbol Th and atomic number 90. A radioactive actinide metal, thorium is one of only two significantly radioactive elements that still occur naturally in large quantities as a primordial element (the other being uranium).[a] It was discovered in 1829 by the Norwegian priest and amateur mineralogist Morten Thrane Esmark[4] and identified by the Swedish chemist Jöns Jacob Berzelius, who named it after Thor, the Norse god of thunder.
A thorium atom has 90 protons and therefore 90 electrons, of which four are valence electrons. Thorium metal is silvery and tarnishes black when exposed to air. Thorium is weakly radioactive: all its known isotopes are unstable, with the seven naturally occurring ones (thorium-227, 228, 229, 230, 231, 232, and 234) havinghalf-lives between 25.52 hours and 14.05 billion years. Thorium-232, which has 142 neutrons, is the most stable isotope of thorium and accounts for nearly all natural thorium, with the other five natural isotopes occurring only in traces: it decays very slowly through alpha decay to radium-228, starting a decay chain named thethorium series that ends at lead-208. Thorium is estimated to be about three to four times more abundant than uranium in the Earth's crust, and is chiefly refined frommonazite sands as a by-product of extracting rare earth metals.
Osmium (from Greek osme (ὀσμή) meaning "smell") is a chemical element with symbol Os and atomic number 76. It is a hard, brittle, bluish-white transition metalin the platinum group that is found as a trace element in alloys, mostly in platinum ores. Osmium is the densest naturally occurring element, with a density of22.59 g/cm3. Its alloys with platinum, iridium, and other platinum group metals are employed in fountain pen nibs, electrical contacts, and other applications where extreme durability and hardness are needed.[3]
9: Handkerchief (12 Days of Christmas with chemistry)
The material of a handkerchief can be symbolic of the social-economic class of the user, not only because some materials are more expensive, but because some materials are more absorbent and practical for those who use a handkerchief for more than style. Handkerchiefs can be made of cotton, cotton-synthetic blend, synthetic fabric, silk, or linen.
Handkerchiefs were also used, especially by children, as an impromptu way to carry around small items when a bag or basket was unavailable. They could also serve as a substitute for a bandage over a small injury. In the United Kingdom, the habit of wearing a handkerchief with tied corners on one's head at the beach has become a seaside postcard stereotype, referenced by the Gumby characters in Monty Python's Flying Circus.
Signals may also be sent by handkerchief, such as the American LGBT handkerchief codes. In Spanish football or in bullfighting, it is a common sight to see supporters waving white handkerchiefs as an expression of deep emotion. It is used both positively, in admiration of an exceptional performance by a team or player, or as a negative sign of disgust at an especially bad performance.
From the late 18th century white handkerchiefs were waved, generally by women (men usually waved their hats), to demonstrate approval at public events such as processions or political rallies.[1][2]
Using handkerchiefs to accentuate hand movements while dancing is a feature of both West African and African-American traditional dance, in the latter case especially in wedding celebrations.[3] Handkerchiefs are also traditional accoutrements in certain kinds of English folk-dance.
Besides their intended use, they could be used for cleaning equipment, polishing shoes, cleaning hands and face, signalling for attention, as a sweat band, neckerchief, as protection from dust inhalation, to repair footwear, cut out pieces to patch clothes, cut up as emergency firearms cleaning patches, Molotov cocktail wick (fire-bomb), hot cooking utensil holder, a makeshift bandage, tourniquet or arm sling.
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