Assertion: astatine | /r/HasProperty | last element
Facets:
Source sentences:
text: The successful measurement fills a long-standing gap in Mendeleev's periodic table, since astatine was the last element present in nature for which this fundamental property was unknown.
text: The results fill a long-standing gap in Mendeleev’s periodic table, since astatine was the last element present in nature for which this fundamental property was unknown.