संसारकै दुर्लभ तथा महंगाे तत्वहरू || Some expensive and rare element of the world || Bishwo Ghatana

Our Next youtube channel : All History:    • The richest Man on Earth - Mansa Musa || स...   Follow on Facebook:   / bishwoghatna   Follow on Twitter:   / bishwoghatana   Platinum Platinum is a chemical element with the symbol Pt and atomic number 78. It is a dense, malleable, ductile, highly unreactive, precious, silverish-white transition metal. Its name is derived from the Spanish term platinum, meaning "little silver". Platinum is a member of the platinum group of elements and group 10 of the periodic table of elements. It has six naturally occurring isotopes. It is one of the rarer elements in Earth's crust, with an average abundance of approximately 5 μg/kg. It occurs in some nickel and copper ores along with some native deposits, mostly in South Africa, which accounts for 80% of the world's production. Because of its scarcity in Earth's crust, only a few hundred tonnes are produced annually, and given its important uses, it is highly valuable and is a major precious metal commodity. Platinum is one of the least reactive metals. It has remarkable resistance to corrosion, even at high temperatures, and is therefore considered a noble metal. Consequently, platinum is often found chemically uncombined as native platinum. Because it occurs naturally in the alluvial sands of various rivers, it was first used by pre-Columbian South American natives to produce artifacts. It was referenced in European writings as early as the 16th century, but it was not until Antonio de Ulloa published a report on a new metal of Colombian origin in 1748 that it began to be investigated by scientists. As of 2020, the value of platinum is around $32.00 per gram ($1,000 per troy ounce) Scandium This is a rare earth metal that was first observed in 1970. It’s used primarily in alloys, and as a matter of fact, that’s probably its only practical application. The price tag, although incomparable to the other elements on this list, is still a lot especially since you would need a lot of the element to make something useful. Sold at $270 per gram, the scandium’s global trade annually of 10 tonnes (about 10 million grams) amounts to $2.7 billion worth of money. That’s a huge sum; but considering how rare the material actually is, it’s even more impressive to think about. Astatine Astatine is a chemical element with the symbol At and atomic number 85. It is the rarest naturally occurring element in the Earth's crust, occurring only as of the decay product of various heavier elements. All of the astatine's isotopes are short-lived; the most stable is astatine-210, with a half-life of 8.1 hours. A sample of the pure element has never been assembled, because any macroscopic specimen would be immediately vaporized by the heat of its own radioactivity. Polonium Polonium is a chemical element with the symbol Po and atomic number 84. A rare and highly radioactive metal with no stable isotopes, polonium is chemically similar to selenium and tellurium, though its metallic character resembles that of its horizontal neighbors in the periodic table: thallium, lead, and bismuth. Due to the short half-life of all its isotopes, its natural occurrence is limited to tiny traces of the fleeting polonium-210 (with a half-life of 138 days) in uranium ores, as it is the penultimate daughter of natural uranium-238. Though slightly longer-lived isotopes exist, they are much more difficult to produce. Music Credit : Martian Cowboy Kevin MacLeod (incompetech.com) Licensed under Creative Commons: By Attribution 3.0 License http://creativecommons.org/licenses/b... http://incompetech.com/ http://audionautix.com/ http://audionautix.com/