Einsteinium-252
Properties and data of the isotope 252Es.
See also: list of Einsteinium isotopes.
General data
Name of the isotope:Einsteinium-252; Es-252Symbol:252Es or 25299EsMass number A:252 (= number of nucleons)Atomic number Z:99 (= number of protons)Neutrons N:153Isotopic mass:252.08298(5) u (atomic weight of Einsteinium-252)Nuclide mass:252.0286785 u (calculated nuclear mass without electrons)Mass excess:77.29537 MeVMass defect:2.017430316 u (per nucleus)Nuclear binding energy:1879.22423477 MeV (per nucleus)
7.45723903 MeV (average binding energy per nucleon)Separation energy:SN = 5.29(5) MeV (first neutron)
SP = 4.13(5) MeV MeV (first proton)Half-life:471.7(19) dDecay constant λ:1.700771001067 × 10-8 s-1Specific activity α:40643978329069 Bq g-1
1098.4859007856 Ci g-1Spin and parity:
(nuclear angular momentum)(5-)Year of discovery:1956
Radioactive Decay
Half-life T½ = 471.7(19) d respectively 4.0754880 × 107 seconds s.
Decay
mode | Daughter | Probability | Decay energy | γ energy
(intensity) |
|---|
| α | 248Bk | 78(2) % | 6.79(5) MeV | |
| EC | 252Cf | 22(2) % | 1.26(5) MeV | |
Parent Nuclides
Direct parent isotope is: 256Md.
Occurrence
Comparison of the natural Einsteinium isotopes including isotopic abundance (mole fraction of the isotope mixture in percent):
| | Atomic Mass ma | Quantity | Half-life | Spin |
|---|
Einsteinium
Isotopic mixture | 252.082979905 u | 100 % | | |
| Isotope 252Es | 252.08298(5) u | 100 % | 471.7(19) d | (5-) |
Isotones and Isobars
The following table shows the atomic nuclei that are isotonic (same neutron number N = 153) and isobaric (same nucleon number A = 252) with Einsteinium-252. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.
| Z | Isotone N = 153 | Isobar A = 252 |
|---|
| 94 | 247Pu | |
| 95 | 248Am | |
| 96 | 249Cm | 252Cm |
| 97 | 250Bk | 252Bk |
| 98 | 251Cf | 252Cf |
| 99 | 252Es | 252Es |
| 100 | 253Fm | 252Fm |
| 101 | 254Md | 252Md |
| 102 | 255No | 252No |
| 103 | 256Lr | 252Lr |
| 104 | 257Rf | |
| 105 | 258Db | |
| 106 | 259Sg | |
| 107 | 260Bh | |
External data and identifiers
Literature and References
[1] - Bernard G. Harvey et al.:
New Isotopes of Einsteinium.
In: Physical Review, (1956), DOI 10.1103/PhysRev.104.1315.
Last update: 2023-04-20
Perma link: https://www.chemlin.org/isotope/einsteinium-252
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