Assertion: astatine's characteristic | /r/HasProperty | mystery
Facets:
value: for a long time
type: TEMPORAL
Source sentences:
text: For a long time, the characteristics of this elusive element were a mystery, but physicists at the CERN physics laboratory in Switzerland have now measured its ionization potential — the amount of energy needed to remove one electron from an atom of astatine, turning it into an ion or a charged particle.
text: For a long time, the characteristics of this elusive element were a mystery, but physicists at the CERN physics laboratory in Switzerland have now measured its ionization potential — the amount of energy needed to remove one electron from an atom of astatine, turning it into an ion or a charged particle.