was a Japanese chemist mainly known for the claimed discovery of element 43 (later known as technetium), which he named nipponium. In fact, he might have discovered, but misidentified, element 75 (later called rhenium). After graduating from the University of Tokyo, he studied under William Ramsay 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 Analytical ...

. For this work, he was awarded a doctorate and the highest prize of the

Tokyo Chemical Society Tokyo (; ja, 東京, , ), officially the Tokyo Metropolis ( ja, 東京都, label=none, ), is the capital and largest city of Japan. Formerly known as Edo, its metropolitan area () is the most populous in the world, with an estimated 37.46 ...

. 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 Emilio may refer to: * Emilio Navaira, a Mexican-American singer often called "Emilio" * Emilio Piazza Memorial School, in Port Harcourt, Rivers State * Emilio (given name) * ''Emilio'' (film), a 2008 film by Kim Jorgensen See also * Emílio (dis ...

), he had apparently isolated element 75, which was otherwise successfully identified in 1925 by

Walter Noddack Walter Noddack (17 August 1893 – 7 December 1960) was a German chemist. He, Ida Tacke (who later married Noddack), and Otto Berg reported the discovery of element 43 and element 75 in 1925. Rhenium They named element 75 rhenium (Latin ''Rhe ...

and

Ida Tacke Ida Noddack (25 February 1896 – 24 September 1978), ''née'' Tacke, 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 (scientist), ...

and named rhenium. 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 transactinid ...

, 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