Assertion: protactinium's isotope | /r/HasProperty | discovered
Facets:
value: independently
type: MANNER
Source sentences:
text: The first isotope to be discovered was Pa-234, which was also called UX2.
text: Protactinium's existence was confirmed in 1918 when another isotope, protactinium-231, was independently discovered and studied by two groups of scientists, Otto Hahn and Lise Meitner of Germany and Frederick Soddy and John Cranston of Great Britain.
text: As the first isotope of neptunium to be discovered has such a short half-life, McMillan and Abelson were unable to prepare a sample that was large enough to perform chemical analysis of the new element using the technology that was then available.
text: Until then, only very short-lived isotopes of protactinium had been discovered, making its properties hard to determine.