Search results
Results from the WOW.Com Content Network
The resistance wire in the thermometer is made of pure platinum (NIST manufactured the wires from platinum bar stock with a chemical purity of 99.999% by weight). [ 77 ] [ 78 ] In addition to laboratory uses, Platinum Resistance Thermometry (PRT) also has many industrial applications, industrial standards include ASTM E1137 and IEC 60751.
Platinum melts at 1768 °C (3215 °F), even higher than iron. [21] Native South Americans worked with it instead by sintering: they combined gold and platinum powders, until the alloy became soft enough to shape with tools. [25] [26]
The earliest known powder metallurgy, and earliest working of platinum in the world, was apparently developed by the cultures of Esmeraldas (northwest Ecuador) before the Spanish conquest [17] Beginning with the La Tolita culture (600 BC – 200 CE), Ecuadorian cultures mastered the soldering of platinum grains through alloying with copper ...
A small box from the burial of the Pharaoh Shepenupet II (died around 650 BC) was found to be decorated with gold-platinum hieroglyphics, [36] but the Egyptians may not have recognised that there was platinum in their gold. [37] [38] First European description of a metal found in South American gold was in 1557 by Julius Caesar Scaliger.
One of the largest bullion coins in the world was the 10,000-dollar Australian Gold Nugget coin minted in Australia, which consists of a full kilogram of 99.9% pure gold. In 2012, the Perth Mint produced a 1-tonne coin of 99.99% pure gold with a face value of $ 1 million AUD, making it the largest minted coin in the world with a gold value of ...
The measurement of sales of popular music starts high relative to the wedding anniversary scale, concentrating on gold and platinum (see gold album).Likewise, credit card companies usually have a "gold card" and a "platinum card" (many formerly had a "silver card" then followed by a "gold card", but due to similarity in appearance between silver and platinum these were often discontinued with ...
2004: First podcast, invented by Adam Curry and Dave Winer, is a program made available in digital format for download over the Internet and it usually features one or more recurring hosts engaged in a discussion about a particular topic or current event. [543] [544] [545] 2005: YouTube, the first popular video-streaming site, was founded
This is an accepted version of this page This is the latest accepted revision, reviewed on 17 November 2024. Development of the table of chemical elements The American chemist Glenn T. Seaborg —after whom the element seaborgium is named—standing in front of a periodic table, May 19, 1950 Part of a series on the Periodic table Periodic table forms 18-column 32-column Alternative and ...