Assertion: einsteinium | /r/HasProperty | atomic number
Facets:
Source sentences:
text: Einsteinium (Es), synthetic chemical element of the actinoid series of the periodic table, atomic number 99.
text: Es; atomic no: 99; half-life of most stable isotope, 252 Es: 276 days
text: Einsteinium (Es), atomic number (Z) 99, is the tenth member of the actinide series.