Assertion: astatine | /r/HasProperty | last occurring element
Facets:
value: naturally
type: MANNER
Source sentences:
text: The measurement fills in a missing piece of the periodic table of elements, because astatine was the last naturally occurring element for which this property was unknown.
text: The measurement fills in a missing piece of the periodic table of elements, because astatine was the last naturally occurring element for which this property was unknown.