Assertion: neptunium's isotope | /r/HasAspect | short half-lives
Facets:
value: within days
type: TEMPORAL
Source sentences:
text: Most other isotopes of neptunium have short half-lives and decay within days.
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.