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was a Japanese chemist mainly known for the claimed discovery of element 43 (later known as
technetium Technetium is a chemical element with the symbol Tc and atomic number 43. It is the lightest element whose isotopes are all radioactive. All available technetium is produced as a synthetic element. Naturally occurring technetium is a spontaneous ...
), which he named nipponium. In fact, he might have discovered, but misidentified, element 75 (later called
rhenium Rhenium is a chemical element with the 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 ...
). After graduating from the
University of Tokyo , abbreviated as or UTokyo, is a public research university located in Bunkyō, Tokyo, Japan. Established in 1877, the university was the first Imperial University and is currently a Top Type university of the Top Global University Project b ...
, he studied under
William Ramsay Sir William Ramsay (; 2 October 1852 – 23 July 1916) was a Scottish chemist who discovered the noble gases and received the Nobel Prize in Chemistry in 1904 "in recognition of his services in the discovery of the inert gaseous element ...
in London, where he worked on the analysis of the rare mineral
thorianite Thorianite is a rare thorium oxide mineral, ThO2. It was originally described by Ananda Coomaraswamy in 1904 as uraninite, but recognized as a new species by Wyndham R. Dunstan. It was so named by Dunstan on account of its high percentage of tho ...
. He extracted and isolated a small amount of an apparently unknown substance from the mineral, which he announced as the discovery of element 43, naming the newly discovered element ''nipponium''. He published his results in 1909 and a notice was also published in the
Journal of the American Chemical Society The ''Journal of the American Chemical Society'' is a weekly peer-reviewed scientific journal that was established in 1879 by the American Chemical Society. The journal has absorbed two other publications in its history, the ''Journal of Analytic ...
. For this work, he was awarded a doctorate and the highest prize of the Tokyo Chemical Society. However, no other researchers were able to replicate his discovery, and the announcement was forgotten. Recent research has indicated that whilst he did not identify element 43 (finally isolated in 1937 by Emilio Segre), he had apparently isolated element 75, which was otherwise successfully identified in 1925 by Walter Noddack and Ida Tacke and named
rhenium Rhenium is a chemical element with the 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 ...
. Ogawa served as president of
Tohoku University , or is a Japanese national university located in Sendai, Miyagi in the Tōhoku Region, Japan. It is informally referred to as . Established in 1907, it was the third Imperial University in Japan and among the first three Designated National ...
between 1919 and 1928. While the name ''nipponium'' could not be reused for another element, element 113 was also discovered by a team of Japanese scientists and is now named
nihonium Nihonium is a synthetic chemical element with the symbol Nh and atomic number 113. It is extremely radioactive; its most stable known isotope, nihonium-286, has a half-life of about 10 seconds. In the periodic table, nihonium is a transactinide ...
, also after Japan. The name was chosen in respectful homage to Ogawa's work.


References

{{DEFAULTSORT:Ogawa, Masataka 20th-century Japanese chemists 1865 births 1930 deaths Discoverers of chemical elements Tohoku University 19th-century Japanese people 20th-century Japanese people Rhenium 19th-century Japanese scientists 20th-century Japanese scientists