Einsteinium-253

Properties and data of the isotope ²⁵³Es.

Content

General data

Name of the isotope:Einsteinium-253; Es-253Symbol:²⁵³Es or 25399EsMass number A:253 (= number of nucleons)Atomic number Z:99 (= number of protons)Neutrons N:154Isotopic mass:253.0848213(13) u (atomic weight of Einsteinium-253)Nuclide mass:253.0305198 u (calculated nuclear mass without electrons)Mass excess:79.01053 MeVMass defect:2.024253932 u (per nucleus)Nuclear binding energy:1885.58039213 MeV (per nucleus)
7.45288693 MeV (average binding energy per nucleon)Separation energy:S_N = 6.36(5) MeV (first neutron)
S_P = 4.3130(26) MeV (first proton)Half-life:20.47(3) dDecay constant λ:3.919167958982 × 10^-7 s^-1Specific activity α:9.328767392387 × 10⁺¹⁴ Bq g^-1
25212.884844291 Ci g^-1Spin and parity:
(nuclear angular momentum)7/2+Magnetic dipole moment:μ(μ_N) = 4.10(7)Quadrupole moment Q:6.7(8) barn (100 fm²)Nuclear g-factor:g_l = 1.1714285714286Year of discovery:1954

Radioactive Decay

Half-life T_½ = 20.47(3) d respectively 1.768608 × 10⁶ seconds s.

Decay mode	Daughter	Probability	Decay energy	γ energy (intensity)
α	²⁴⁹Bk	< 100 %	6.73924(5) MeV
SZ	div	0.0000087 %

Parent Nuclides

Direct parent isotopes are: ²⁵⁷Md, ²⁵³Fm, ²⁵³Cf.

Isotones and Isobars

The following table shows the atomic nuclei that are isotonic (same neutron number N = 154) and isobaric (same nucleon number A = 253) with Einsteinium-253. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.

OZ	Isotone N = 154	Isobar A = 253
95	²⁴⁹Am
96	²⁵⁰Cm
97	²⁵¹Bk	²⁵³Bk
98	²⁵²Cf	²⁵³Cf
99	²⁵³Es	²⁵³Es
100	²⁵⁴Fm	²⁵³Fm
101	²⁵⁵Md	²⁵³Md
102	²⁵⁶No	²⁵³No
103	²⁵⁷Lr	²⁵³Lr
104	²⁵⁸Rf	²⁵³Rf
105	²⁵⁹Db
106	²⁶⁰Sg
107	²⁶¹Bh