Rutherfordium-256m1

Properties and data of the isotope ²⁵⁶Rf.

Content

See also: list of Rutherfordium isotopes.

General data

Name of the isotope:Rutherfordium-256m1; Rf-256m1Symbol:²⁵⁶Rf or 256104RfMass number A:256 (= number of nucleons)Atomic number Z:104 (= number of protons)Neutrons N:152Isotopic mass:256.101152(19) u (atomic weight of Rutherfordium-256m1)
Excitation energy: 1120 keVNuclide mass:256.0441086 u (calculated nuclear mass without electrons)Mass excess:94.22248 MeVMass defect:2.02971856 u (per nucleus)Nuclear binding energy:1890.67066033 MeV (per nucleus)
7.38543227 MeV (average binding energy per nucleon)Half-life:25(2) μsDecay constant λ:27725.887222398 s^-1Specific activity α:6.52223430937 × 10⁺²⁵ Bq g^-1
1.762766029560 × 10⁺¹⁵ Ci g^-1Spin and parity:
(nuclear angular momentum)(5-)

Radioactive Decay

Half-life T_½ = 25(2) μs respectively 2.5 × 10^-5 seconds s.

Decay mode	Daughter	Probability	Decay energy	γ energy (intensity)
Iso	²⁵⁶Rf	?
SZ	div	?

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
²⁵⁶Rf		6.67(10) ms	0+
^256m2Rf	1400 keV	17(2) μs	(8-)
^256m3Rf	2200 keV	27(5) μs

Isotones and Isobars

The following table shows the atomic nuclei that are isotonic (same neutron number N = 152) and isobaric (same nucleon number A = 256) with Rutherfordium-256m1. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.

OZ	Isotone N = 152	Isobar A = 256
94	²⁴⁶Pu
95	²⁴⁷Am
96	²⁴⁸Cm
97	²⁴⁹Bk
98	²⁵⁰Cf	²⁵⁶Cf
99	²⁵¹Es	²⁵⁶Es
100	²⁵²Fm	²⁵⁶Fm
101	²⁵³Md	²⁵⁶Md
102	²⁵⁴No	²⁵⁶No
103	²⁵⁵Lr	²⁵⁶Lr
104	²⁵⁶Rf	²⁵⁶Rf
105	²⁵⁷Db	²⁵⁶Db
106	²⁵⁸Sg