Isotopes of einsteinium

{{Short description|none}} {{Infobox einsteinium isotopes}} Einsteinium (₉₉Es) is a synthetic element, and thus a standard atomic weight cannot be given. Like all synthetic elements, it has no stable isotopes. The first isotope to be discovered (in nuclear fallout from the Ivy Mike H-bomb test) was ²⁵³Es in 1952. There are 18 known radioisotopes, from ²⁴⁰Es to ²⁵⁷Es, and 8 nuclear isomers. The longest-lived isotope is ²⁵²Es with a half-life of 471.7 days or 1.291 years; the second longest, ²⁵⁴Es with half-life of 275.7 days is more available.

== List of isotopes == {{Anchor|Einsteinium-239|Einsteinium-258}}

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{{Isotopes table |symbol=Es |refs=NUBASE2020, AME2020 II, IsotopeFRIB, IsomerFRIB |notes=m, unc(), mass#, exen#, spin(), spin#, SF, EC, IT, discoveryname }} |-id=Einsteinium-240 | rowspan=3|²⁴⁰Es | rowspan=3 style="text-align:right" | 99 | rowspan=3 style="text-align:right" | 141 | rowspan=3|240.06895(39)# | rowspan=3 style="text-align:center" | [https://www.nndc.bnl.gov/discovery/abstracts/99/240.pdf 2017] | rowspan=3|{{val|6.0|(17)|u=s}} | α (70%) | ²³⁶Bk | rowspan=3|4−# |- | β⁺ (30%) | ²⁴⁰Cf |- | β⁺, SF (0.16%) | (various) |-id=Einsteinium-241 | ²⁴¹Es | style="text-align:right" | 99 | style="text-align:right" | 142 | 241.06859(25)# | style="text-align:center" | [https://www.nndc.bnl.gov/discovery/abstracts/99/241.pdf 1996] | {{val|4.3|2.4|1.2|u=s}}<ref>{{cite journal |last1=Khuyagbaatar |first1=J. |last2=Albers |first2=H. M. |last3=Block |first3=M. |last4=Brand |first4=H. |last5=Cantemir |first5=R. A. |last6=Di Nitto |first6=A. |last7=Düllmann |first7=Ch. E. |last8=Götz |first8=M. |last9=Götz |first9=S. |last10=Heßberger |first10=F. P. |last11=Jäger |first11=E. |last12=Kindler |first12=B. |last13=Kratz |first13=J. V. |last14=Krier |first14=J. |last15=Kurz |first15=N. |last16=Lommel |first16=B. |last17=Lens |first17=L. |last18=Mistry |first18=A. |last19=Schausten |first19=B. |last20=Uusitalo |first20=J. |last21=Yakushev |first21=A. |title=Search for Electron-Capture Delayed Fission in the New Isotope ²⁴⁴Md |journal=Physical Review Letters |date=1 October 2020 |volume=125 |issue=14 |article-number=142504 |doi=10.1103/PhysRevLett.125.142504 |pmid=33064498 |bibcode=2020PhRvL.125n2504K |s2cid=223546973 |url=http://urn.fi/URN:NBN:fi:jyu-202010066084 }}</ref> | α | ²³⁷Bk | 3/2−# |-id=Einsteinium-242 | rowspan=3|²⁴²Es<ref>{{cite journal | last1=Khuyagbaatar | first1=J. | last2=Cantemir | first2=R. A. | last3=Düllmann | first3=Ch. E. | last4=Jäger | first4=E. | last5=Kindler | first5=B. | last6=Krier | first6=J. | last7=Kurz | first7=N. | last8=Lommel | first8=B. | last9=Schausten | first9=B. | last10=Yakushev | first10=A. | title=Decay properties of the neutron-deficient isotope Es 242 | journal=Physical Review C | volume=109 | issue=3 | date=2024-03-18 | article-number=034311 | issn=2469-9985 | doi=10.1103/PhysRevC.109.034311| arxiv=2408.01714 }}</ref> | rowspan=3 style="text-align:right" | 99 | rowspan=3 style="text-align:right" | 143 | rowspan=3|242.06957(28)# | rowspan=3 style="text-align:center" | [https://www.nndc.bnl.gov/discovery/abstracts/99/242.pdf 1994] | rowspan=3|{{val|16.9|(8)|u=s}} | β⁺ | ²⁴²Cf | rowspan=3|2+# |- | α (41%) | ²³⁸Bk |- | β⁺, SF (1.5%) | (various) |-id=Einsteinium-243 | rowspan=2|²⁴³Es | rowspan=2 style="text-align:right" | 99 | rowspan=2 style="text-align:right" | 144 | rowspan=2|243.06951(22)# | rowspan=2 style="text-align:center" | [https://www.nndc.bnl.gov/discovery/abstracts/99/243.pdf 1973] | rowspan=2|{{val|22.1|(14)|u=s}} | α (61%) | ²³⁹Bk | rowspan=2|(7/2+) |- | β⁺? (39%) | ²⁴³Cf |-id=Einsteinium-243m | rowspan=3 style="text-indent:1em" | ^243mEs<ref group="n" name="order">Order of ground state and isomer is uncertain.</ref> | rowspan=3 colspan=3 style="text-indent:2em" | 50(50)#&nbsp;keV | rowspan=3 style="text-align:center" | [https://www.nndc.bnl.gov/discovery/isomers/abstracts/99/243Es-1.pdf 2025] | rowspan=3|>50#&nbsp;μs | IT? | ²⁴³Es | rowspan=3|3/2−# |- | α? | ²³⁹Bk |- | β⁺? | ²⁴³Cf |-id=Einsteinium-244 | rowspan=3|²⁴⁴Es | rowspan=3 style="text-align:right" | 99 | rowspan=3 style="text-align:right" | 145 | rowspan=3|244.07088(20)# | rowspan=3 style="text-align:center" | [https://www.nndc.bnl.gov/discovery/abstracts/99/244.pdf 1973] | rowspan=3|{{val|37|(4)|u=s}} | β⁺ (95%) | ²⁴⁴Cf | rowspan=3|6+# |- | α (5%) | ²⁴⁰Bk |- | β⁺, SF (0.011%) | (various) |-id=Einsteinium-245 | rowspan=2|²⁴⁵Es | rowspan=2 style="text-align:right" | 99 | rowspan=2 style="text-align:right" | 146 | rowspan=2|245.07119(18)# | rowspan=2 style="text-align:center" | [https://www.nndc.bnl.gov/discovery/abstracts/99/245.pdf 1967] | rowspan=2|{{val|1.11|(6)|u=min}} | β⁺ (51%) | ²⁴⁵Cf | rowspan=2|(3/2−) |- | α (49%) | ²⁴¹Bk |-id=Einsteinium-245m | rowspan=3 style="text-indent:1em" | ^245mEs<ref group="n" name="order"/> | rowspan=3 colspan="3" style="text-indent:2em" | 30(15)#&nbsp;keV | rowspan=3 style="text-align:center" | (1967)<ref group="n" | name="notm">Half-life not measured, not included in discovery database</ref> | rowspan=3|>50#&nbsp;μs | IT? | ²⁴⁵Es | rowspan=3|7/2+# |- | α? | ²⁴¹Bk |- | β⁺? | ²⁴⁵Cf |-id=Einsteinium-246 | rowspan=3|²⁴⁶Es | rowspan=3 style="text-align:right" | 99 | rowspan=3 style="text-align:right" | 147 | rowspan=3|246.07281(10) | rowspan=3 style="text-align:center" | [https://www.nndc.bnl.gov/discovery/abstracts/99/246.pdf 1954] | rowspan=3|{{val|7.5|(5)|u=min}} | β⁺ (90.1%) | ²⁴⁶Cf | rowspan=3|4−# |- | α (9.9%) | ²⁴²Bk |- | β⁺, SF (0.003%) | (various) |-id=Einsteinium-247 | rowspan=2|²⁴⁷Es | rowspan=2 style="text-align:right" | 99 | rowspan=2 style="text-align:right" | 148 | rowspan=2|247.073622(21) | rowspan=2 style="text-align:center" | [https://www.nndc.bnl.gov/discovery/abstracts/99/247.pdf 1967] | rowspan=2|{{val|4.55|(26)|u=min}} | β⁺ (93%) | ²⁴⁷Cf | rowspan=2|(7/2+) |- | α (7%) | ²⁴³Bk |-id=Einsteinium-247m | rowspan=3 style="text-indent:1em" | ^247mEs<ref group="n" name="order" /> | rowspan=3 colspan=3 style="text-indent:2em" | 50(50)#&nbsp;keV | rowspan=3 style="text-align:center" | (2001)<ref group="n" name=notm /> | rowspan=3|>20#&nbsp;μs | IT? | ²⁴⁷Es | rowspan=3|(3/2−) |- | α? | ²⁴³Bk |- | β⁺ | ²⁴⁷Cf |-id=Einsteinium-248 | rowspan=3|²⁴⁸Es | rowspan=3 style="text-align:right" | 99 | rowspan=3 style="text-align:right" | 149 | rowspan=3|248.07547(6)# | rowspan=3 style="text-align:center" | [https://www.nndc.bnl.gov/discovery/abstracts/99/248.pdf 1956] | rowspan=3|{{val|24|(3)|u=min}} | β⁺ (99.75%) | ²⁴⁸Cf | rowspan=3|2−# |- | α (0.25%) | ²⁴⁴Bk |- | β⁺, SF (3.5×10⁻⁴%) | (various) |-id=Einsteinium-249 | rowspan=2|²⁴⁹Es | rowspan=2 style="text-align:right" | 99 | rowspan=2 style="text-align:right" | 150 | rowspan=2|249.07641(3)# | rowspan=2 style="text-align:center" | [https://www.nndc.bnl.gov/discovery/abstracts/99/249.pdf 1956] | rowspan=2|{{val|102.2|(6)|u=min}} | β⁺ (99.43%) | ²⁴⁹Cf | rowspan=2|7/2+ |- | α (0.57%) | ²⁴⁵Bk |-id=Einsteinium-250 | ²⁵⁰Es | style="text-align:right" | 99 | style="text-align:right" | 151 | 250.07861(11)# | style="text-align:center" | [https://www.nndc.bnl.gov/discovery/abstracts/99/250.pdf 1956] | {{val|8.6|(1)|u=h}} | β⁺ | ²⁵⁰Cf | 6(+) |-id=Einsteinium-250m | style="text-indent:1em" | ^250mEs<ref group="n" name="order"/> | colspan="3" style="text-indent:2em" | 200(150)#&nbsp;keV | style="text-align:center" | [https://www.nndc.bnl.gov/discovery/isomers/abstracts/99/250Es-1.pdf 1970] | {{val|2.22|(5)|u=h}} | β⁺ | ²⁵⁰Cf | 1(−) |-id=Einsteinium-251 | rowspan=2|²⁵¹Es | rowspan=2 style="text-align:right" | 99 | rowspan=2 style="text-align:right" | 152 | rowspan=2|251.079991(6) | rowspan=2 style="text-align:center" | [https://www.nndc.bnl.gov/discovery/abstracts/99/251.pdf 1956] | rowspan=2|{{val|33|(1)|u=h}} | EC (99.5%) | ²⁵¹Cf | rowspan=2|3/2− |- | α (0.5%) | ²⁴⁷Bk |-id=Einsteinium-251m | rowspan=2 style="text-indent:1em" | ^251mEs | rowspan=2 colspan=3 style="text-indent:2em" | 8.4(10)&nbsp;keV | rowspan=2 style="text-align:center" | ----<ref group="n" name=notm /> | rowspan=2 | >200#&nbsp;μs | IT? | ²⁵¹Es | rowspan=2|(7/2+) |- | EC? | ²⁵¹Cf |-id=Einsteinium-252 | rowspan=2|²⁵²Es | rowspan=2 style="text-align:right" | 99 | rowspan=2 style="text-align:right" | 153 | rowspan=2|252.08298(5) | rowspan=2 style="text-align:center" | [https://www.nndc.bnl.gov/discovery/abstracts/99/252.pdf 1956] | rowspan=2|{{val|471.7|(19)|u=d}} | α (78%) | ²⁴⁸Bk | rowspan=2|(4+) |- | EC (22%) | ²⁵²Cf |-id=Einsteinium-253 | rowspan=2|²⁵³Es<ref group="n">Most common isotope</ref> | rowspan=2 style="text-align:right" | 99 | rowspan=2 style="text-align:right" | 154 | rowspan=2|253.0848212(13) | rowspan=2 style="text-align:center" | [https://www.nndc.bnl.gov/discovery/abstracts/99/253.pdf 1954] | rowspan=2|{{val|20.47|(3)|u=d}} | α | ²⁴⁹Bk | rowspan=2|7/2+ |- | SF (8.7×10⁻⁶%) | (various) |-id=Einsteinium-253m | style="text-indent:1em" | ^253mEs | colspan=3 style="text-indent:2em" | 106(4)&nbsp;keV | style="text-align:center" | (1993)<ref group="n" name=notm /> | >10#&nbsp;μs | IT? | ²⁵³Es | 3/2−# |-id=Einsteinium-254 | rowspan=3|²⁵⁴Es | rowspan=3 style="text-align:right" | 99 | rowspan=3 style="text-align:right" | 155 | rowspan=3|254.088024(3) | rowspan=3 style="text-align:center" | [https://www.nndc.bnl.gov/discovery/abstracts/99/254.pdf 1954] | rowspan=3|{{val|275.7|(5)|u=d}} | α<ref group="n">Theoretically capable of electron capture to ²⁵⁴Cf</ref> | ²⁵⁰Bk<!-- According to NUBASE, 254Es favors α decay to 250m2Bk --> | rowspan=3|7+ |- | β⁻ (1.74×10⁻⁴%) | ²⁵⁴Fm |- | SF (<3×10⁻⁶%) | (various) |-id=Einsteinium-254m | rowspan=5 style="text-indent:1em" | ^254mEs | rowspan=5 colspan="3" style="text-indent:2em" | 80.4(11)&nbsp;keV | rowspan=5 style="text-align:center" | [https://www.nndc.bnl.gov/discovery/isomers/abstracts/99/254Es-1.pdf 1956] | rowspan=5|{{val|39.3|(2)|u=h}} | β⁻ (98%) | ²⁵⁴Fm | rowspan=5|2+ |- | IT (<3%) | ²⁵⁴Es |- | α (0.32%) | ²⁵⁰Bk |- | EC (0.076%) | ²⁵⁴Cf |- | SF (<0.045%) | (various) |-id=Einsteinium-255 | rowspan=3|²⁵⁵Es | rowspan=3 style="text-align:right" | 99 | rowspan=3 style="text-align:right" | 156 | rowspan=3|255.090274(12) | rowspan=3 style="text-align:center" | [https://www.nndc.bnl.gov/discovery/abstracts/99/255.pdf 1954] | rowspan=3|{{val|39.8|(12)|u=d}} | β⁻ (92.0%) | ²⁵⁵Fm | rowspan=3|(7/2+) |- | α (8.0%) | ²⁵¹Bk |- | SF (0.0041%) | (various) |-id=Einsteinium-256 | rowspan=2|²⁵⁶Es | rowspan=2 style="text-align:right" | 99 | rowspan=2 style="text-align:right" | 157 | rowspan=2| 256.09360(11)# | rowspan=2 style="text-align:center" | [https://www.nndc.bnl.gov/discovery/abstracts/99/256.pdf 1981] | rowspan=2|{{val|7.6|u=h}} | β⁻ | ²⁵⁶Fm | rowspan=2|7+# |- | β⁻, SF (0.002%) | (various) |-id=Einsteinium-256m | style="text-indent:1em" |^256mEs<ref group="n" name="order"/> | colspan="3" style="text-indent:2em" | 0(100)#&nbsp;keV | style="text-align:center" | [https://www.nndc.bnl.gov/discovery/isomers/abstracts/99/256Es-1.pdf 1989] | {{val|25.4|(12)|u=min}} | β⁻ | ²⁵⁶Fm | 0+# |-id=Einsteinium-257 | ²⁵⁷Es | style="text-align:right" | 99 | style="text-align:right" | 158 | 257.09598(44)# | style="text-align:center" | [https://www.nndc.bnl.gov/discovery/abstracts/99/257.pdf 1987] | {{val|7.7|(2)|u=d}} | β⁻ | ²⁵⁷Fm | 7/2+# {{Isotopes table/footer}}

== References == {{Reflist}}

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Category:Isotopes of einsteinium Category:Einsteinium Einsteinium