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Frederick Soddy FRS was an English radiochemist who explained, with Ernest Rutherford, that radioactivity is due to the transmutation of elements, now known to involve nuclear reactions. He also proved the existence of isotopes of certain radioactive elements. In 1921 he received the Nobel Prize in Chemistry "for his contributions to our knowledge of the chemistry of radioactive substances, and his investigations into the origin and nature of isotopes". Soddy was a polymath who mastered chemistry, nuclear physics, statistical mechanics, finance and economics.
Hafnium is a chemical element; it has symbol Hf and atomic number 72. A lustrous, silvery gray, tetravalent transition metal, hafnium chemically resembles zirconium and is found in many zirconium minerals. Its existence was predicted by Dmitri Mendeleev in 1869, though it was not identified until 1922, by Dirk Coster and George de Hevesy, making it one of the last two stable elements to be discovered. Hafnium is named after Hafnia, the Latin name for Copenhagen, where it was discovered.
Ruthenium is a chemical element; it has symbol Ru and atomic number 44. It is a rare transition metal belonging to the platinum group of the periodic table. Like the other metals of the platinum group, ruthenium is unreactive to most other chemicals. Karl Ernst Claus, a Russian-born scientist of Baltic-German ancestry, discovered the element in 1844 at Kazan State University and named ruthenium in honor of Russia. Ruthenium is usually found as a minor component of platinum ores; the annual production has risen from about 19 tonnes in 2009 to some 35.5 tonnes in 2017. Most ruthenium produced is used in wear-resistant electrical contacts and thick-film resistors. A minor application for ruthenium is in platinum alloys and as a chemistry catalyst. A new application of ruthenium is as the capping layer for extreme ultraviolet photomasks. Ruthenium is generally found in ores with the other platinum group metals in the Ural Mountains and in North and South America. Small but commercially important quantities are also found in pentlandite extracted from Sudbury, Ontario, and in pyroxenite deposits in South Africa.
Rhenium is a chemical element; it has symbol Re and atomic number 75. It is a silvery-gray, heavy, third-row transition metal in group 7 of the periodic table. With an estimated average concentration of 1 part per billion (ppb), rhenium is one of the rarest elements in the Earth's crust. It has the third-highest melting point and second-highest boiling point of any element at 5869 K. It resembles manganese and technetium chemically and is mainly obtained as a by-product of the extraction and refinement of molybdenum and copper ores. It shows in its compounds a wide variety of oxidation states ranging from −1 to +7.
Technetium is a chemical element; it has symbol Tc and atomic number 43. It is the lightest element whose isotopes are all radioactive. Technetium and promethium are the only radioactive elements whose neighbours in the sense of atomic number are both stable. All available technetium is produced as a synthetic element. Naturally occurring technetium is a spontaneous fission product in uranium ore and thorium ore, or the product of neutron capture in molybdenum ores. This silvery gray, crystalline transition metal lies between manganese and rhenium in group 7 of the periodic table, and its chemical properties are intermediate between those of both adjacent elements. The most common naturally occurring isotope is 99Tc, in traces only.
John Kerr FRS was a Scottish physicist and a pioneer in the field of electro-optics. He is best known for the discovery of what is now called the Kerr effect.
Group 7, numbered by IUPAC nomenclature, is a group of elements in the periodic table. It contains manganese (Mn), technetium (Tc), rhenium (Re) and bohrium (Bh). This group lies in the d-block of the periodic table, and are hence transition metals. This group is sometimes called the manganese group or manganese family after its lightest member; however, the group itself has not acquired a trivial name because it belongs to the broader grouping of the transition metals.
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Nebulium was a proposed element found in astronomical observation of a nebula by William Huggins in 1864. The strong green emission lines of the Cat's Eye Nebula, discovered using spectroscopy, led to the postulation that an as yet unknown element was responsible for this emission. In 1927, Ira Sprague Bowen showed that the lines are emitted by doubly ionized oxygen (O2+), and no new element was necessary to explain them.
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Ida Noddack, néeTacke, was a German chemist and physicist. In 1934 she was the first to mention the idea later named nuclear fission. With her husband Walter Noddack, and Otto Berg, she discovered element 75, rhenium. She was nominated three times for the Nobel Prize in Chemistry.
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Rhenium disulfide is an inorganic compound of rhenium and sulfur with the formula ReS2. It has a layered structure where atoms are strongly bonded within each layer. The layers are held together by weak Van der Waals bonds, and can be easily peeled off from the bulk material.
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Max Born was a widely influential German physicist and mathematician who was awarded the 1954 Nobel Prize in Physics for his pivotal role in the development of quantum mechanics. Born won the prize primarily for his contributions to the statistical interpretation of the wave function, though he is known for his work in several areas of quantum mechanics as well as solid-state physics, optics, and special relativity. Born's entry in the Biographical Memoirs of Fellows of the Royal Society included thirty books and 330 papers.
References
- ↑ Kern, Serge (1877). "On a new metal, davyum". Philosophical Magazine. Series 5. 4 (23): 158–159. doi:10.1080/14786447708639315.
- ↑ Kern, Serge (1877). "On a new metal, davyum". Philosophical Magazine. Series 5. 4 (26): 395–396. doi:10.1080/14786447708639360.
- ↑ "Davyum1". Nature. 17 (430): 245–246. 1878. Bibcode:1878Natur..17..245.. doi: 10.1038/017245a0 .
- ↑ Swjaginzew, O.; Korsunski, M.; Seljakow, N. (1927). "Dwimangan in Platinerzen". Zeitschrift für Angewandte Chemie. 40 (9): 256. Bibcode:1927AngCh..40..256S. doi:10.1002/ange.19270400905.
- ↑ Friend, J. Newton; Druce, J. G. F. (1950). "Davyum, a Possible Precursor of Rhenium (Element 75)". Nature. 165 (4203): 819. Bibcode:1950Natur.165..819F. doi: 10.1038/165819a0 . PMID 15423460. S2CID 1276756.
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