Editing Einsteinium (section)

===Isotopes===
{{main|Isotopes of einsteinium}}
Eighteen isotopes and four [[nuclear isomer]]s are known for einsteinium, with [[mass number]]s 240–257.{{NUBASE2020|ref}} All are radioactive; the most stable one, {{sup|252}}Es, has half-life 471.7 days.<ref>{{cite journal|last1=Ahmad|first1=I.|title=Half-life of the longest-lived einsteinium isotope-252Es|journal=Journal of Inorganic and Nuclear Chemistry|volume=39|pages=1509–1511|date=1977|doi=10.1016/0022-1902(77)80089-4|issue=9|last2=Wagner|first2=Frank}}</ref> The next most stable isotopes are {{sup|254}}Es (half-life 275.7 days),<ref>{{cite journal|last1=McHarris|first1=William|last2=Stephens|first2=F.|last3=Asaro|first3=F.|last4=Perlman|first4=I.|title=Decay Scheme of Einsteinium-254|journal=Physical Review|volume=144|pages=1031–1045|date=1966|doi=10.1103/PhysRev.144.1031|issue=3|bibcode = 1966PhRv..144.1031M }}</ref> {{sup|255}}Es (39.8 days), and {{sup|253}}Es (20.47 days). All the other isotopes have half-lives shorter than 40 hours, most shorter than 30 minutes. Of the five isomers, the most stable is {{sup|254m}}Es with a half-life of 39.3 hours.{{NUBASE2020|ref}}