Rutherfordium-253m

Properties and data of the isotope ²⁵³Rf.

Content

See also: list of Rutherfordium isotopes.

General data

Name of the isotope:Rutherfordium-253m; Rf-253mSymbol:²⁵³Rf or 253104RfMass number A:253 (= number of nucleons)Atomic number Z:104 (= number of protons)Neutrons N:149Isotopic mass:253.10044(44) u (atomic weight of Rutherfordium-253m)
Excitation energy: +y keVNuclide mass:253.0433966 u (calculated nuclear mass without electrons)Mass excess:93.55926 MeVMass defect:2.004435812 u (per nucleus)Nuclear binding energy:1867.11993226 MeV (per nucleus)
7.37992068 MeV (average binding energy per nucleon)Half-life:48 (+17-10) μsDecay constant λ:14440.566261666 s^-1Specific activity α:3.437277633399 × 10⁺²⁵ Bq g^-1
9.289939549727 × 10⁺¹⁴ Ci g^-1Spin and parity:
(nuclear angular momentum)

Radioactive Decay

Half-life T_½ = 48 (+17-10) μs respectively 4.8 × 10^-5 seconds s.

Decay mode	Daughter	Probability	Decay energy	γ energy (intensity)
α		?
SZ		< 100 %

Nuclear Isomers

Nuclear isomers or excited states with the activation energy in keV related to the ground state.

Nuclear Isomer	Excitation Energy	Half-life	Spin
²⁵³Rf		11 (+3-6) ms	(7/2+)

Isotones and Isobars

The following table shows the atomic nuclei that are isotonic (same neutron number N = 149) and isobaric (same nucleon number A = 253) with Rutherfordium-253m. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.

OZ	Isotone N = 149	Isobar A = 253
91	²⁴⁰Pa
92	²⁴¹U
93	²⁴²Np
94	²⁴³Pu
95	²⁴⁴Am
96	²⁴⁵Cm
97	²⁴⁶Bk	²⁵³Bk
98	²⁴⁷Cf	²⁵³Cf
99	²⁴⁸Es	²⁵³Es
100	²⁴⁹Fm	²⁵³Fm
101	²⁵⁰Md	²⁵³Md
102	²⁵¹No	²⁵³No
103	²⁵²Lr	²⁵³Lr
104	²⁵³Rf	²⁵³Rf