Nobelium-258

Properties and data of the isotope ²⁵⁸No.

Content

General data

Name of the isotope:Nobelium-258; No-258Symbol:²⁵⁸No or 258102NoMass number A:258 (= number of nucleons)Atomic number Z:102 (= number of protons)Neutrons N:156Isotopic mass:258.09820(11) u (atomic weight of Nobelium-258)Nuclide mass:258.0422533 u (calculated nuclear mass without electrons)Mass excess:91.47271 MeVMass defect:2.05168016 u (per nucleus)Nuclear binding energy:1911.12775896 MeV (per nucleus)
7.40747193 MeV (average binding energy per nucleon)Separation energy:S_N = 6.84(10) MeV (first neutron)
S_P = 4.80(10) MeV (first proton)Half-life:1.2(2) msDecay constant λ:577.62265046662 s^-1Specific activity α:1.348265490310 × 10⁺²⁴ Bq g^-1
36439607846219 Ci g^-1Spin and parity:
(nuclear angular momentum)0+Year of discovery:1989

Radioactive Decay

Half-life T_½ = 1.2(2) ms respectively 1.2 × 10^-3 seconds s.

Decay mode	Daughter	Probability	Decay energy	γ energy (intensity)
SF	div.	≤ 100 %

Parent Nuclides

Direct parent isotope is: ²⁵⁸Md.

Isotones and Isobars

The following table shows the atomic nuclei that are isotonic (same neutron number N = 156) and isobaric (same nucleon number A = 258) with Nobelium-258. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.

OZ	Isotone N = 156	Isobar A = 258
96	²⁵²Cm
97	²⁵³Bk
98	²⁵⁴Cf
99	²⁵⁵Es
100	²⁵⁶Fm	²⁵⁸Fm
101	²⁵⁷Md	²⁵⁸Md
102	²⁵⁸No	²⁵⁸No
103	²⁵⁹Lr	²⁵⁸Lr
104	²⁶⁰Rf	²⁵⁸Rf
105	²⁶¹Db	²⁵⁸Db
106	²⁶²Sg	²⁵⁸Sg
107	²⁶³Bh
108	²⁶⁴Hs