Attribute iridium is a member of the platinum group, which is white and slightly yellow. Its density is 22.65 grams per cubic centimeter. In contrast, the density of lead is 1 1.34g/cm3, and that of iron is 7.874g/cm3. According to the chemical explanation,
Iridium is not affected by acids, bases or most other chemicals. This property is very useful when making objects exposed to these materials.
Iridium (Andrei Marincas Shutterstock) is actually other properties of iridium. According to the research of Los Alamos National Laboratory:
Atomic number (number of protons in its nucleus): 77 atomic symbol (on the periodic table of elements): infrared atomic weight (average atomic mass): 192.2 17 melting point: 4435f(2446c) boiling point: 8002.4f(4428c) stable isotope: 2, press. These two substances are iridium-19 1(37.3%) and iridium-193(62.7%) respectively. Several chemists may have discovered iridium at the same time as 1803. It is said that British chemist Smithsonian tennant, French chemist H.V. Collet de scottie, A.F. Focroix and N.L. Walklin all found iridium in the acid-insoluble residue of platinum ore. However, Tanneng is usually praised.
Tanneng discovered iridium by dissolving crude platinum in diluted aqua regia (a mixture of nitric acid and hydrochloric acid), and then treating the black residue with alkali and acid in turn. After this treatment, the residue was separated into two new elements. At Royal College London, he announced his discovery and named one element iridium and the other osmium. The name iridium comes from the Latin iris, which means rainbow. Although the metal itself is not rainbow color, it is called rainbow color because it contains many kinds of compounds.
Because iridium has strong corrosion resistance, the standard instrument rod is made of 90% platinum and 10% iridium. However, in 1960, this benchmark is replaced by the definition of meters. This instrument is redefined according to the orange-red spectral line of krypton. However, the prototype kilogram, which defines kilogram internationally, is also made of platinum and platinum-iridium alloy, and it is still used all over the world.
Today, iridium is commercially recovered as a by-product of copper or nickel mining. Iridium-bearing ores have been found in Brazil, the United States, Myanmar, South Africa, Russia and Australia.
Pure iridium is very rare in the crust. There is only about one in two billion iridium in the earth's crust. According to the chemical explanation,
"Iridium is one of the densest and rarest natural elements on earth. It is very dense and mainly exists in the earth's core, not in the earth's crust, "said Amanda Simson, an assistant professor of chemical engineering at the University of New Haven, KDSP and KDSP, but some iridium exists in the earth's crust. 1980, scientist Luis Alvarez and his son Water Alvarez discovered a large amount of iridium in a certain part of the earth's crust, which was distributed all over the earth's surface. "They speculated that it was caused by a meteor and linked it to the extinction of dinosaurs 66 million years ago. Sison explained:
Although it is brittle to use, according to the Encyclopedia Britannica, iridium can work if it is heated to a white heat of 2200 to 2700 degrees Fahrenheit (1200 to 1500 degrees Celsius). The main purpose of iridium is to harden platinum by making platinum alloy dspe.
It is also used to manufacture equipment needed for high temperature and electrical contact. It is also used in some optical lenses to reduce glare. A compound of osmium and iridium, called osmium iridium, is used to locate the pen tip and compass. Super jewelry is also made of iridium and platinum alloys.
Additional resources
Jefferson Laboratory: Iridium National Medical Library: Studies on Schiff Base Complexes and Amino Acid-Iridium Complexes of Some Iridium (III) in Organic Synthesis