Ogawa Masataka
Ogawa Masataka ( Japanese 小川 正 孝 ; * February 21, 1865 , † July 11, 1930 ) was a Japanese chemist . He became known through the supposed discovery of the element with the atomic number 43, which was later named technetium .
Life
After graduating from Tokyo University with a degree in chemistry , he was sent to London by the Japanese government to study with Nobel Prize winner William Ramsay . There he worked on the analysis of the rare mineral thorianite , which was first found in Ceylon in 1904 . From this he isolated an unknown substance. Based on the line spectrum , he postulated that he had found a new element. Ramsay suggested the name Nipponium after Ogawa's homeland .
After his return to Japan in 1906, he continued studying the substance and assigned it an equivalent weight of about 50. From this he postulated that he had found the missing element in the periodic table between molybdenum and ruthenium . In 1910 he was honored by the Japanese Chemical Society for his discovery, although his results could not be replicated. Internationally, his claim was soon forgotten.
From 1911 he taught as a professor at Tōhoku University , whose rector he became in 1919.
Recent research suggests that Ogawa actually isolated rhenium with atomic number 75. Both elements were proven by Walter Noddack and Ida Tacke in 1925 , but this was not recognized for element 43 - Emilio Segrè was only able to provide the undisputed proof in 1937 .
Web links
Individual evidence
| personal data | |
|---|---|
| SURNAME | Ogawa, Masataka |
| ALTERNATIVE NAMES | 小川 正 孝 (Japanese) |
| BRIEF DESCRIPTION | Japanese chemist |
| DATE OF BIRTH | February 21, 1865 |
| DATE OF DEATH | July 11, 1930 |