Rutherfordium-255

Properties and data of the isotope ²⁵⁵Rf.

Content

General Data

Radioactive Decay

Parent Nuclides

Isotones und Isobares

See also: list of Rutherfordium isotopes.

General data

Name of the isotope:Rutherfordium-255; Rf-255Symbol:²⁵⁵Rf or 255104RfMass number A:255 (= number of nucleons)Atomic number Z:104 (= number of protons)Neutrons N:151Isotopic mass:255.10127(12) u (atomic weight of Rutherfordium-255)Nuclide mass:255.0442266 u (calculated nuclear mass without electrons)Mass excess:94.3324 MeVMass defect:2.020935644 u (per nucleus)Nuclear binding energy:1882.48942677 MeV (per nucleus)
7.38231148 MeV (average binding energy per nucleon)Separation energy:S_N = 6.94(31) MeV (first neutron)
S_P = 2.83(32) MeV (first proton)Half-life:1.68(19) sDecay constant λ:0.41258760747616 s^-1Specific activity α:9.743767408963 × 10⁺²⁰ Bq g^-1
26334506510.712 Ci g^-1Spin and parity:
(nuclear angular momentum)(9/2-)Year of discovery:1975

Radioactive Decay

Half-life T_½ = 1.68(19) s.

Decay mode	Daughter	Probability	Decay energy
α	²⁵¹No	42(9) %	9.055(4) MeV
SZ	^div.	58(9) %
EE/β⁺	²⁵⁵Lr	< 1 %	4,38(12) MeV

Parent Nuclides

Direct parent isotope is: ²⁵⁹Sg.

Isotones and Isobars

The following table shows the atomic nuclei that are isotonic (same neutron number N = 151) and isobaric (same nucleon number A = 255) with Rutherfordium-255. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.

OZ	Isotone N = 151	Isobar A = 255
92	²⁴²U
93	²⁴⁴Np
94	²⁴⁵Pu
95	²⁴⁶Am
96	²⁴⁷Cm
97	²⁴⁸Bk
98	²⁴⁹Cf	²⁵⁵Cf
99	²⁵⁰Es	²⁵⁵Es
100	²⁵¹Fm	²⁵⁵Fm
101	²⁵²Md	²⁵⁵Md
102	²⁵³No	²⁵⁵No
103	²⁵⁴Lr	²⁵⁵Lr
104	²⁵⁵Rf	²⁵⁵Rf
105	²⁵⁶Db	²⁵⁵Db