Rutherfordium-258

Properties and data of the isotope ²⁵⁸Rf.

Contents

See also: List of individual Rutherfordium isotopes (and general data sources).

General data

Name of the isotope:Rutherfordium-258; Rf-258Symbol:²⁵⁸Rf or 258104RfMass number A:258 (= number of nucleons)Atomic number Z:104 (= number of protons)Neutrons N:154Nucleon pairing (Z - N):even - evenNuclear ratio (N/Z ratio):1.4807692307692 (= neutron-proton ratio)Neutron excess (N-Z):50Isotopic mass:258.10343(3) u (atomic weight of Rutherfordium-258)Nuclide mass:258.0463866 u (calculated nuclear mass without electrons)Mass excess:96.34442 MeVMass defect:2.044770392 u (per nucleus)Nuclear binding energy:1904.69135153 MeV (per nucleus)
7.38252462 MeV (average binding energy per nucleon)Separation energy:S_N = 7.60(3) MeV (first neutron)
S_P = 8.61(5) MeV (first proton)Half-life:12.0(12) msDecay constant λ:57.762265046662 s^-1Specific activity α:1.348265490310 × 10⁺²³ Bq g^-1
3643960784621.9 Ci g^-1Spin and parity:
(nuclear angular momentum)0+Year of discovery:1969

Radioactive Decay

Half-life T_½ = 12.0(12) ms respectively 1.20 × 10^-2 seconds s.

Decay mode	Daughter	Probability	Decay energy	γ energy (intensity)
α	²⁵⁴No	4.9(16) %	9.19(3) MeV
SZ	div	95.1(16) %

Isotones and Isobars

The following table shows the atomic nuclei that are isotonic (same neutron number N = 154) and isobaric (same nucleon number A = 258) with Rutherfordium-258. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.

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