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  1. More Images

    Promethium

    Chemical element with the atomic number of 61

    Promethium is a chemical element with symbol Pm and atomic number 61. All of its isotopes are radioactive; it is extremely rare, with only about 500–600 grams naturally occurring in the Earth's crust at any given time. Promethium is one of the only two radioactive elements that are both preceded and followed in the periodic table by elements with stable forms, the other being technetium. Chemically, promethium is a lanthanide. Promethium shows only one stable oxidation state of +3. In 1902 Bohuslav Brauner suggested that there was a then-unknown element with properties intermediate between those of the known elements neodymium and samarium; this was confirmed in 1914 by Henry Moseley, who, having measured the atomic numbers of all the elements then known, found that the element with atomic number 61 was missing. In 1926, two groups claimed to have isolated a sample of element 61; both "discoveries" were soon proven to be false. Wikipedia

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  2. livescience.com

    May 29, 2024"Promethium was the last puzzle piece among those elements," Popovs said. The ligand provided a way to have a stable complex for all of the lanthanides — the same element ratios and the same ...
  3. en.wikipedia.org

    Promethium nuclear isomers may decay to other promethium isotopes and one isotope (145 Pm) has a very rare alpha decay mode to stable praseodymium-141. [4] The most stable isotope of the element is promethium-145, which has a specific activity of 139 Ci/g (5.1 TBq/g) and a half-life of 17.7 years via electron capture.
  4. britannica.com

    promethium (Pm), chemical element, the only rare-earth metal of the lanthanide series of the periodic table not found in nature on Earth. Conclusive chemical proof of the existence of promethium, the last of the rare-earth elements to be discovered, was obtained in 1945 (but not announced until 1947) by American chemists Jacob A. Marinsky, Lawrence E. Glendenin, and Charles D. Coryell, who ...
    Author:The Editors of Encyclopaedia Britannica
  5. May 22, 2024Then, using X-ray spectroscopy, they determined the properties of the complex, including the length of the promethium chemical bond with neighboring atoms — a first for science and a longstanding missing piece to the periodic table of elements. Promethium is very rare; only about a pound occurs naturally in the Earth's crust at any given time.
  6. newscientist.com

    May 22, 2024Chemistry Mysterious element promethium finally reveals its chemical properties. The highly unstable radioactive element promethium is hard to study in the lab, but chemists have now coaxed it ...
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  8. sciencetimes.com

    Jun 14, 2024A Big Step Forward in Purity and Analysis. Scientists have been confused for a long time about promethium, one of the 15 lanthanide elements because it is hard to find and unstable. Even though ...
  9. zmescience.com

    May 24, 2024"There are thousands of publications on lanthanides' chemistry without promethium. That was a glaring gap for all of science," said Dr. Santa Jansone-Popova from Oak Ridge National Laboratory.
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